Xisanqi Subdistrict is a subdistrict inside of Haidian District, Beijing, China. It borders Huilongguan and Huoying Subdistricts to the north, Dongxiaokou and Dongsheng Towns to the east, Aoyuncun Subdistrict to the south, and Qinghe Subdistrict to the west. Its population was 157,643 in 2020.