Battle of Pingxingguan The Battle of Pingxingguan ( ) , also commonly called the " Great Victory of Pingxingguan " ( ) in Mainland China , was an engagement fought between the 8th Route Army of the Communist Party of China and the Imperial Japanese Army on September 25 , 1937 . It resulted in a minor , morale - boosting victory for the Chinese Communists with an otherwise insignificant number of casualties and a small amount of captured supplies . Background . After the capture of Beiping ( present Beijing ) at the end of July , Japanese forces advanced along the Beiping - Suiyuan railway line to Inner Mongolia . Having anticipated the move , Chiang Kai - shek had appointed the Shanxi warlord Yan Xishan as Pacification Director of Taiyuan . Theoretically Yan had authority over all the Chinese military forces in his theatre of operations , including Lin Biao ' s 115th Division of the Communist 8th Route Army , Liu Ruming ' s ex - Kuomintang troops and various Central Army contingents responsible to Chiang Kai - shek . In reality these forces operated independently from Yan ' s provincial army . Japanese forces , mainly the 5th Division and 11th Independent Mixed Brigade , moved out from Beiping and advanced on Huailai County in Chahar . A Japanese column advanced quickly into Shanxi , making use of the railway which the Chinese did not attempt to destroy . The Chinese abandoned Datong on September 13 , falling back to a line from Yanmenguan on the Great Wall east to the mountain pass of Pingxingguan . Yan Xishan ' s troops became more demoralised as the Japanese exerted their air supremacy . The main body of the Japanese 5th Division , under the command of Itagaki Seishiro , advanced from Huaili to invade northeastern Shanxi . Although it had a motorised transport column , its rate of advance was limited by the poor roads . By the time they reached the Shanxi border , Lin Biao ' s 115th Division , after a forced march from Shaanxi , was in place at Pingxingguan on September 24 to ambush the Japanese army . Order of Battle Battle of Pingxingguan The battle . The pass of Pingxingguan was a narrow defile worn through the loess , with no exit for several kilometres except the road itself . Lin ' s division were able to ambush two columns of mainly transportation and supply units and virtually annihilate the trapped Japanese forces . On September 25 , the 21st brigade of the Japanese 5th Division stationed at LingQiu received a request from the 21st Regiment that they urgently needed supplies due to falling temperature . The supply troops of the 21st Regiment set out with 70 horse - drawn vehicle s with 50 horses , filled with clothes , food , ammunition and proceeded westwards towards Pingxingguan . Around 10 : 00 , the supply column passed into a defile with the two sides rising up more than 10 meters ; they were heading towards Cai Jia Yu about 3 km away . At the same time , a motorized column of Japanese supply troops in about 80 trucks left Guan Gou and headed east . Both of these non - combat formations entered into the ambush set by the 115th division after 10 a . m . on the 25th and were largely wiped out . A relief force consisting of the 3rd Battalion of the 21st Regiment was rebuffed by Chinese troops and suffered almost 100 casualties . Lin Biao ' s troops eventually withdrew from the battlefield , allowing the Japanese to finally reach the site of the ambush on September 28 . The total , the Japanese casualties in the battle have been estimated at 400 to 500 and the Chinese at about 400 . The Chinese forces destroyed about 70 trucks and an equal number of horse - drawn carts and captured 100 rifles , 10 light machine guns , 1 gun , 2000 shells as well as some clothing and food . Evaluation . The Kuomintang official history of the Second Sino - Japanese War deals with it in a sentence , without any credit to the communists . Communist accounts , on the other hand , describe Pingxingguan as a typical example of " Red " guerrilla tactics , inspired by Mao Zedong ' s conceptualization of " People ' s war " . Japanese losses were greatly exaggerated for propaganda purposes . However , like the victory at the Battle of Taierzhuang , Pingxingguan was explained by Japan as Japanese officers succumbing to what they came to call " victory disease " . After a series of easy victories against their opponents , they failed to take elementary precautions . Japanese commanders seldom repeated the operational blunders that had led to Pingxingguan . Nonetheless , the battle gave the Chinese a major boost in morale and credence to the Communists in the eyes of the people . The battle was constantly cited by CPC brass as an example of their commitment to battling the Japanese occupation .