Based on the SWEM2D model, a 2D flow and sediment numerical model is built including Yangshan harbor, the Yangtze estuary and Hangzhou bay. The measured data observed from Yangshan harbor in May 2004 shows that the vertical shear of the suspended sediment plays such a small impact on its sediment transport that a 2D sediment numerical model can almost represent the sediment transport near Yangshan harbor.The model result is in good agreement with the measured data which observed from Yangshan harbor and its adjacent areas in May 2004. On that basis, a transport velocity of suspended sediment during the spring, middle and neap tide in the Yangshan harbor and its adjacent areas is calculated. The result shows that in the Yangshan harbor, the Euler transport plays predominant role in suspended sediment transport while the Stokes drift and tidal pump play secondary. The high concentration of suspended sediment in the west of the Yangshan harbor is mainly caused by the convergence of the sediment transport from the Yangtze estuary and Hangzhou bay. Near the east of Nanhui beach, the suspended sediment transport separates into two parts: one flows northward, the other, firstly,flows towards Hangzhou bay along the underwater sediment channel at the south of Nanhui beach and then flows to Yangshan harbor by the suspended sediment transport from Hangzhou bay.