Wu Junsheng was born in a peasant family in Changtu, Fengtien province (today Liaoning), on November 23, 1863. He joined a cavalry troop in 1880, crushed the Manchu independence plan (supported by the Japanese) in 1912. He supported Yuan Shikai's monarchy in 1915, and supported Zhang Zuolin's effort to seize Manchuria. He was rewarded with the Military and Civil governorship of Heilongjiang in March 1921. Promoted to commander of the 5th Army in 1924. He held those posts until to June 1928 when he died, on the train in the assassination of Zhang Zuolin.