The 18th Division was resurrected in September 1937 as a square division as a part of general military build-up following the start of the Second Sino-Japanese War. As part of the IJA 10th Army under the overall command of the Japanese Central China Area Army it was deployed to the Chinese mainland, as an emergency reinforcement force to supplement the Japanese Shanghai Expeditionary Army in China after the Second Shanghai Incident. The Japanese "18th division" subsequently participated in the Battle of Nanjing and the subsequent atrocities known as the Nanking Massacre. From September 1938, the division came under the control of the IJA 21st Army, and participated in the Canton Operation and the invasion and occupation of Guangdong Province under the command of Lieutenant General Seiichi Kuno. The division remained in China through the 1939–40 Winter Offensive under the command of Lieutenant General Harukichi Hyakutake.