In 1937 the North China Area Army had chased Song Zheyuan's 29th Army to the south along the Jinpu Railway (see Tianjin–Pukou Railway Operation) after his defeat in the Battle of Lugou Bridge.
I 1937 havde den japanske hær i Nordkina jaget Song Zheyuans 29. armé sydpå langs Jinpu jernbanen (se Tianjin–Pukou jernbaneoperationen) efter hans nederlag i Slaget ved Lugou Bridge.