Abstract: The design of any city flood control project must be based on reliable hydrologic studies. For cities near coast, it is necessary not only to know the regulation of the flood regimen of a stream, but also to be concerned largely with wave action, tide movement, ocean currents and similar phenomena. Therefore, the investigation and analysis of the rules will be greatly conducive to the design of coastal engineering, and also be important in preparation of the national standard of the city flood control.