Considering protection and controlled utilization,a mathematical model based on traditional method was built up.In the light of its own characteristics of Qingxiushan Forest Park,calculation factor was dete rmined and dynamic threshold and instantaneous threshold were calculated through this factor.It was conclude that tourist capacity should be used as environmental capacity of Qingxiushan Forest Park.The daily and annual environmental capacity were 34197 and 10259100 person times.Under this condition,ecological environment of Qingx...