Abstract:This paper briefly describes the historical evolution, hydrological characteristics and water environment change process of Suzhou Creek, reviews the first, second, and third stages of Suzhou River environmental comprehensive treatment project since 1998 and the related scientific research work, and analyzes the achievements of the previous treatment by using the water quality change process of the main stream over years. The results show that the improvement of water quality index is better in the first stage, but the influence of the second and third stages is not obvious. But when the suburban river is further improved, the water quality of the main stream is further improved. Finally, in view of the overall plan of the fourth stage of Suzhou Creek comprehensive treatment project, it is pointed out that a wider and more thorough treatment of the water environment of branchs of Suzhou Creek will improve the water environment of the main stream. However, to restore the ecological function of Suzhou Creek, which is “clear water, green bank, and fish swimming in rivers”, it needs a long process, and the upstream in Jiangsu Province needs to be controlled simultaneously.