In July 1937, the Second Sino-Japanese War broke out. In December, Li Pinxian served as deputy commander-in-chief of the fifth theater (commander-in-chief Li Zongren) and commander-in-chief of the Eleventh Army (three jurisdictions). He participated in the Battle of Shanghai, Battle of Xuzhou, and Battle of Taierzhuang. He made military achievements by giving the Japanese army a big blow. In June 1938, he participated in the Battle of Wuhan and served as the commander of the Fourth Army Corps of the Wuhan Defense Army. In October of the same year, the Japanese army occupied Wuhan, and the army led by Li Pinxian was more combative than the friendly army. After that, the army went to Hubei Province for recuperation and reorganization. In April 1939, he participated in the Battle of Suixian-Zaoyang (known as the Xiangdong Battle in Japan) and fought against the four Japanese divisions to stop the Japanese offensive and make military contributions.