By　means　of　researching　an　office　building　in　Beijing　area　and　making　simulation　analysis　on　the　data　concerning　energy　saving　effect　of　building　sunshade,　the　paper　investigates　the　effects　of　different　sunshade　systems　on　indoor　temperature　and　cooling　load,　and　theologically　selects　the　optimal　sunshade　system　best　suitable　to　Beijing　area.　The　research　shows　that　if　a　suitable　inner　sunshade　system　is　applied,　an　energy　saving　effect　of　over　30%　can　reached.