Abstract: Considering the complexity，urban green space system was divided into 3 subsystems，including landscape green space，ecological green space，recreational and disaster prevention green space. According to the principle of synergetics，coordination evaluation model of urban green space system was established. Taking Heshan city as the research object，we determined the threshold of each parameter component，and then calculated its value. The results showed that the coordination degree of green space system in Heshan was 0.52，indicating that the urban green space system in Heshan was in a basic synergistic state. In the three subsystems，landscape green space subsystem had the largest contribution with value of 0.62，while ecological green space subsystem had the minimum contribution with value of 0.48， contribution of recreation and disaster prevention green space subsystem was in the middle level with value of 0.50.