Abstract: The Qiantang River basin is located in the monsoon climate zone along cast and south coasts,with abundant water vapour and plentiful rainfall.Within the basin,precipitation obviously corresponds to runoff,and runoff coefficient is stable.There are 11-year and 14-year quasi-cycle changes of natural runoff. There are three types of rainstorm and flood:typhoon,plum rain,thunder rainstorm.The river contains less silt,belonging to the clear water river with much more water and less sand.The Qiantang River is rich in water energy resources.Its mouth is a strong tide one.Tide energy is striking.The drop of the upper reaches is greal,so water energy resources are abundant.With the increase of industrial,agricultural and domestic water,to research deeply the hydrological law of the Qiantang River is very benefitial to utilizing rationally water resources and water energy resources,and promoting the economic development of the basin.