With the start of the Second Sino-Japanese War 27 July 1937, the 6th Division was assigned to the Japanese China Garrison Army, and immediately started to act in the ongoing Battle of Beiping–Tianjin. Afterward, it participated in Beiping–Hankou Railway Operation. 20 October 1937, the division was re-subordinated to the 10th Army and attacked the Chinese troops concentration at Hangzhou Bay. By December 1937, it shifted west to participate together with the 18th Division and 114th Division in the Battle of Nanking and ultimately in the Nanking Massacre. On 14 February 1938, the 6th Division was subordinated to the Central China Expeditionary Army and in May 1938 entered the Battle of Xuzhou. 15 May 1938, the 106th Division was split from the 6th Division. Actions in the Battle of Wuhan began in June 1938, and the division was subsequently withdrawn to Japan. In 1940, the 47th infantry regiment was transferred to the 48th division, converting the 6th Division to the triangular division format.