This study aimed at the evaluation of the service function of public green space under single or compound factors at regional scale using a Geographic Information System (GIS) and remote sensing, urban planning extension, Beijing city as our study area. Urban heat island, accommodate asylum population, green rate, absorption of carbon dioxide per year, and release of oxygen per year were collected, processed, and constructed into a spatial database using GIS and remote sensing data. Grade of sevice function of public green space and the contrabutions to service function of singal factor and compound-factor were analysed and mapped using multi-factor hierarchical cover model. The results showed: Nearly zero of the public green space might have severe poor service function. Slight poor service function accounte for 23.6%. Intermediate service function accounted for 45.1%. Public green space, with good or better service function, respectively accounted for 29.1% and 2.1%.