Abstract: With use of the experimental results of water quantity and water quality of the overflow from some representative drainage systems to Suzhou Creek in rainy days and treatment the technology of the storage tanks,the integrated model of hydrodynamics and the water quality of pipe networks about the drainage systems and the river networks for Suzhou creek is set up,combined with the physical model, the influence of controlling pollution of the overflow from the initial rainwater storage tanks to Suzhou Creek and its water quality are studied in detail in 8 kinds of 1-12-h design rainfall condition.