Zu Mao (onyomi: So Mo) is an officer who served under Sun Jian. He was one of the first four generals to fight alongside his lord to defeat Dong Zhuo. When his lord was defeated during the campaign against Dong Zhuo, it was said that during their flight, he secretly exchanged his helmet with that of his lord's and successfully diverted the enemy's attention.
Zu Mao was born in Wu Commandery in Yang Province and was one of the first generals to join Sun Jian. When Sun Jian's army attacked Liangdong during the campaign against Dong Zhuo, Xu Rong was sent by Dong Zhuo to defend the area. Xu Rong led a quick surprise attack and Sun Jian was forced to flee. However, Sun Jian was unable to shake off pursuit, and Zu Mao exchanged headgear with Sun Jian. The soldiers under Xu Rong chased after Zu Mao, allowing Sun Jian to escape. Zu Mao later hung Sun Jian's headgear onto a half-burnt pillar, and hid himself in the tall grasses nearby. The enemies surrounded the pillar and approached cautiously till they realized they had been fooled, whereupon they retreated. Zu Mao's fate henceforth was not documented.