The statistical characteristics of the essential factors and their correlation, which have a grat impact on the water level of the Huangpujiang River,are analyzed in this paper.A joint probability distribution model of the tide level is established in the Wusongkou and the rainfall in the Taihu Lake area for calculating the probability of occurrence of the specified design tide level in Wusongkou,the design rainfall in Taihu Lake area and the corresponding rainfall in the reach.Furthermore,the design water level curve along the Huangpujiang River is obtained on the basis of employing a hydrodynamic model with the enveloping curve method.The results would help to determine the long-term flood protection criteria in Shanghai City and offer useful reference to the construction of the Wusong Storm Tide Gate.