In March 1940, the Eighth Route Army concentrated 13 regiments in the Taihang Mountains to attack Nationalist forces stationed in Huai, causing their main force to rout and withdraw from the defense area.
At the end of 1939, Zhao Tong, an anti-Japanese guerrilla commander appointed by the National Government, was ambushed by the Eighth Route Army while leading his force north, and the unit was wiped out.