After the Battle of Pingxingguan, although the Japanese army's front suffered a heavy setback, the Fifth Division still did not abandon the established strategic objectives. On 28 September, the Japanese captured Ru Yue Ri, and the Chinese army retreated to Tiejiaoling, west of Fanzhi. The Japanese army followed them again, and after a bloody battle, Tiejiaoling was lost, and Fanzhi also fell that night. The rear road of the Chinese defenders at Pingxingguan was cut off, and the situation was critical. In order to avoid encirclement, the Chinese army abandoned Pingxingguan and moved to the line from Daixian and Yanmen Pass to Yangfangkou in Wutai Mountain. After occupying Ruyueri, Tiejiaoling, and Pingxingguan, the Japanese army joined forces in Fanzhi, captured Daixian on October 1, crossed Yangfangkou with 30 eyes, and attacked Ningwu, a key point in northern Jin. At this point, the defense line of the Great Wall of the Chinese army was broken through by the enemy, and the Japanese army approached Xinkou.

In retaliation for the heavy damage of the Chinese army to Chahar in northern Cyprus, the Japanese army began to concentrate its navy and aviation forces to launch a new attack on October 1. The north road is directed to Guangfu and Chenjiaxing by the 11th Division of Yamamuro Zongwu; The 3rd, 9th, 13th, and 101st Divisions of the South Road were concentrated to force their way across Fuzaobang and attack Dachang and Nanxiang in order to cut off the defenders from the outside world in the Dachang to Jiangwan area and make them a lone army.

At the same time, the main force of the Japanese North China Front went south along the Jinpu Road and went straight to Jinan. However, Han Fuqu in the Fifth Theater had no choice but to do nothing in the face of the Japanese army's frantic attack, except to order the troops to constantly retreat.

At the same time, more than 1,000 Japanese troops attacked Yangmingbao, engaged in a fierce battle with the 1st Division of the Chinese 19th Army, and invaded Yangmingbao. On the 2nd, with the cooperation of aircraft and artillery, they attacked Laoxian. On the 4th, the Japanese mixed 15th Brigade made a detour from the west of Laoxian County and attacked Yuanping Town. At this time, the Wei Lihuang troops transferred from Shijiazhuang on the Pinghan Road had not yet arrived, and the Jin Sui army, which had been transferred from Wutai Mountain to Xinkou, could only arrive two days later, and the situation was very critical. In order to give the main force enough time to assemble at Xinkou and fight a decisive battle with the enemy, the Second Theater Command ordered the Chinese defenders to hold on to Laoxian and Yuanping until the follow-up troops arrived. The officers and men of the 407th Regiment of the 19th Army suffered extremely heavy casualties. On the 7th, the number of Japanese troops besieging Laoxian increased to 5 or 6,000 men. The Japanese army used more than 20 planes and more than 30 field heavy artillery pieces to bomb the county town indiscriminately for six hours, the northern city wall was destroyed, the 41st Regiment suffered all casualties, and the enemy took the opportunity to break in. The defenders of the east and west city walls fought bravely and engaged in hand-to-hand combat with the enemy. At night, officers at all levels of the Chinese defenders personally led their troops to block the enemy, and the Japanese army continued unabated, and the situation was irreparable. On the 8th, Commander Wang Jingguo had to lead the rest of his troops to break through the siege, and Laoxian fell.

After a small number of Japanese troops remained in the occupied area, the army continued to move south, and the front of the army was directed towards Pingyuan Town. The defenders of Yuanping Town were Jiang Yuzhen's 196th Brigade. In order to enable the main force to complete the assembly at Xinkou, the headquarters of the Second Theater Commander ordered him to "defend Yuanping for seven days (counting from October 1), even if there is one soldier left." On the way to transfer the troops from Dai County to Haraping, the Japanese army was already chasing behind them. At a place still 20 miles away from Yuanping, Jiang's brigade was independently mixed with the enemy into the 15th Brigade to engage fire, and fought and retreated. Outside Yuanping Town, Jiang Yuzhen ordered his subordinates to build fortifications and defend railways and highways. Relying on superior equipment, the Japanese army, with the cooperation of aircraft, heavy artillery, and combat vehicles, launched a fierce attack on Harada. Jiang Yuzhen came to command, the enemy attacked many times and was repulsed, the Jiang brigade suffered heavy casualties day by day, the position gradually shrunk, the Japanese army formed an encirclement posture of Yuan Ping, and after the last day, the Jiang brigade had to retreat into the city.

By the 7th day, the Japanese army broke through from the northeast corner of the city, occupied the eastern half of the city, and fought against Jiang Brigade across the street. At this time, Jiang Yuzhen received another order and ordered him to guard for another 3 days. He immediately said: "Swear to fight to the death, and never leave Sishi without orders." "After the fall of Laoxian on October 8, a large number of Japanese troops surrounded Yuanping, and the northwest part of the city was also captured. At this time, the 5,000 people of Jiang Brigade, only 2 or 300 people, were besieged in the northeast corner of the city, but the soldiers were not afraid, and under the leadership of Jiang Yuzhen, they launched street battles with the enemy. It lasted until midnight on October 10 and completed the task of defending the city. After that, Jiang Yuzhen led the rest of the troops to break through the siege, but unexpectedly, she was hit by an enemy shell outside the city and was martyred. On the 11th, the Japanese army occupied Harapyeong.

After the fall of Laoxian and Yuanping, Xinkou was completely under the direct attack of the Japanese army. Xinkou is the gateway to Taiyuan in the north of Shanxi Province, and it is the last line of defense to defend Taiyuan. In order to defend Taiyuan, the Kuomintang Second Theater Command concentrated six group armies, a total of 31 divisions, 13 brigades, and about 280,000 people. The specific deployment of troops is; The 9th, 15th, 17th, 19th and 14th Group Armies and other units formed the Central Corps, which was commanded by Deputy Commander-in-Chief Wei Lihuang and was responsible for guarding the front-line positions of Caijiagang, Lingshan, Nanhuaihua and Yangmingbao; The 18th Group Army (except the 120th Division), the 73rd Division, the 101st Division and other divisions formed the right wing corps, commanded by Zhu De, commander-in-chief of the 18th Group Army, to guard the first-line positions on Wutai Mountain; The 68th, 61st, 120th Divisions and the 7th Independent Brigade formed the Left Wing Corps, commanded by Yang Aiyuan, commander-in-chief of the Sixth Group Army, to defend the first-line position from Heiyu Village to Yangfangkou; With the 34th Army, the 35th Army, and the 66th Division as reserves, and under the command of Fu Zuoyi, commander-in-chief of the Seventh Group Army, they responded to all parties in the vicinity of Dingxiang and Xinxian.

The Japanese army participated in the Battle of Xinkou with a total of about 3 divisions and more than 70,000 people, and was equipped with more than 350 cannons, more than 150 combat vehicles and 300 aircraft.

On October 12, the Second Theater Command readjusted its deployment, and transferred Fu Zuoyi's reserve corps to join the Central Corps to fight and continue to fight with the enemy on the front line of Xinkou. On the 13th, the Japanese army mobilized more than 5,000 troops, under the cover of aircraft, artillery and combat vehicles, to storm the central position of Xinkou - Nanhuaihua, in an attempt to implement a central breakthrough. Under the fierce attack of the Japanese army, the position of Nanhuaihua was almost razed to the ground. Although the Chinese defenders were trapped in scorched earth, they still bravely killed the enemy, fought fiercely until late at night, and the position changed hands 13 times, and finally surrounded and annihilated the enemy who broke through to Nanhuaihua.

On the 14th, the Japanese army increased its strength by several thousand and once again stormed the position in Nanhuaihua, and the Chinese defenders fought more fiercely with the Japanese invaders. The 15th Army of the Chinese defenders on the right flank fought with the enemy until the evening, driving the Japanese army to the foot of Lingshan; The 10th Division on the left flank routed the enemy and recovered Jiulianzhuang and other places, but the main position of Nanhuaihua fell into the hands of the enemy, and there were breaches in the defensive line, and the tug-of-war became more and more fierce.

On 15 October, in order to further expand the results of the battle, annihilate the enemy, and regain the central position, the Chinese Second Theater Command transferred about five brigades of the Ninth Army and the 21st Division to launch a counteroffensive against the positions occupied by the Japanese army under the command of Hao Mengling, commander-in-chief of the Central Corps and commander of the Ninth Army. The Chinese army attacked from the front, besieging the enemy from three sides.

At 2 a.m. on the 16th, the counterattack began. Under the command of Hao Mengling, the Chinese army took a few hills, and at about 5 o'clock, the sky was light, Hao Mengling was anxious to rush to the forward position of the 5th Brigade to command the operation, and the officers and soldiers told him that it was very dangerous to block a section of the road ahead by enemy fire, and persuaded him to write a written order to send someone to send it. After that, he resolutely ran to the forward position, and when he passed through the position only 200 meters away from the enemy, he was unfortunately shot and died heroically at the age of 39. At the same time, Liu Jiaqi, commander of the 54th Division, and Zheng Lianzhen, commander of the 5th Independent Brigade, were also killed and martyred.

Due to the brave fighting of the Chinese defenders at Xinkou, the Japanese began to attack the central position of Xinkou on October 13, and by the end of October, the two sides had been fighting fiercely for half a month, and the Japanese army had never been able to fully occupy these areas.

The Japanese army encountered stubborn resistance from the Chinese army near Xinkou and made little progress, so they sent troops along the Zhengtai Road to attack Taiyuan in mid-October. The Chinese garrison stationed at the Niangzi Pass on Zhengtai Road was the headquarters of Huang Shaohong, deputy commander of the Kuomintang Second Theater of Operations. Beginning on October 11, Japanese troops and Chinese defenders fought in the area around Zhengtai Road and Niangzi Pass. On the 14th, the Chinese defenders received reinforcements from Sun Lianzhong's headquarters near Niangzi Pass, and immediately counterattacked the invading enemy, killing hundreds of enemies on the same day. On the 15th, most of the more than 1,500 enemies who had invaded the gate were annihilated, and at dawn the next day, they launched an attack on all fronts, fighting hand-to-hand with the enemy and annihilating the enemy. However, by the 19th, the Japanese reinforcements had increased in large numbers, and with the strong cooperation of aircraft and artillery, although the Chinese army continued to fight bravely, it eventually turned into a disadvantage due to the disparity in strength. On the 26th, Niangzi Pass was captured by the Japanese army. Niangzi Pass was lost, and the Chinese defenders of Xinkou were in a situation of being attacked on their backs. On November 2, the Second Theater Command had no choice but to order the defenders of Xinkou to retreat to defend Taiyuan. Xinri, which was sprinkled with the blood of Chinese generals, was occupied by the Japanese army on the same day, and the battle turned to Taiyuan.

The Battle of Kou began on October 11 and ended on November 2, 23 days of hard fighting, after the Battle of Nanhuaihua, the Battle of Honggou, the Battle of Dabaishui and other countless battles of all sizes, the battle formed a confrontation, the Japanese army changed its commander three times to no avail, becoming the most fierce battle in the North China battlefield in the early days of the Anti-Japanese War, and it was also the battle that lasted the longest and suffered the largest casualties on both sides. The anti-Japanese army successively joined the battle, with a total strength of about 100,000 people in 16 divisions, and more than 50,000 people were killed and wounded; The Japanese army invested more than 50,000 troops, and more than 20,000 were killed and wounded. Although the Chinese side lost this battle and paid heavy sacrifices, due to the heroic resistance of the Chinese defenders, a large number of enemy troops were consumed, time was gained, and the Japanese army's battle plan for the Hebei Plain was destroyed, so that the Chinese army on the Pinghan Line could withdraw south.

After the Battle of Xinkou, the Japanese army originally wanted to take Taiyuan by victory, but the base camp directly ordered the Fifth Division, the main force of the Japanese army on the Xinkou front, to immediately go north to attack Datong, an important town in northern Shanxi.

On November 6, the 9th Brigade of the 5th Division of the Japanese Army captured Shuozhou, and the army continued to advance in the direction of Datong.

Shuozhou. Temporary Headquarters of the 5th Division of the Japanese Army.

The commander of the Fifth Division, Seishiro Itagaki sat proudly on the main seat, he had reason to be proud and had reason to be proud, soon after the start of the war, he led the army to break through the military town of Nankou, where the 13th Army of the elite division of the Chinese army was stationed, and inflicted heavy losses on the elite of the central army of the Chinese government.

A few days ago, he had captured Xinkou, the gateway to Taiyuan, if it weren't for such an order from the base camp, he would probably have captured Taiyuan, the old nest of his old classmate Yan Xishan, by now.