In 1920, the former town of Agongdian (阿公店, A-kong-tiàm) was renamed Gangshan by the ruling Japanese and was made the site of a Japanese airbase. The town suffered heavy bombardment in World War II. Following the Kuomintang takeover after the war, Gangshan continued to host Gangshan Air Base (Kangshan Air Base). The township has a strong military veteran's presence as well.
The township is part of the suburbs of Kaohsiung City which encompass 10 cities (or townships) out of 18 in the official Kaohsiung Metro Area.