The 31st Group Army is a military formation of China's People's Liberation Army and one of three active group armies belonging to the Nanjing Military Region. It is based at Xiamen, Fujian and is composed of the 86th Infantry Division and the 91st Motorized Infantry Division, along with an armored brigade, an air defense brigade, a surface-to-air missile regiment, an artillery regiment, and an engineer regiment. It is considered a Category A unit, with priority status in terms of readiness, strength, and modern equipment. Based on its training activities and positioning, its primary mission is presumed to be the invasion of Taiwan. Its unit ID number is 73111.