During the final stages of the Chinese Civil War, the Ma fought for the Kuomintang side in defiance until the communists wiped out his cavalry and took Gansu in August 1949, just months before the establishment of the People's Republic of China. Upon the arrival of communist forces, Ma Hongbin had little possibility of winning and joined to communists' side. He was appointed vice-chairman (later restyled vice-governor) of Gansu province.