The adopted son of Park Eun-sik, Park Si-chang was appointed deputy chief of staff of the Korean Liberation Army headquarters when it was founded in September 1940, and served as acting commander in Xi'an that October. He became a member of the Provisional Government's Military Affairs Committee in October 1942 and a State Council member in March 1943; after liberation he commanded the Liberation Army's Shanghai garrison detachment, directing the repatriation of overseas Koreans and Liberation Army soldiers.