Due to the lack of the long series of tidal level data,it is difficult to determine the design water level.According to the tide data of 16 tide stations in the sea area of Zhejiang throughout the year,we calculate characteristic tidal level and design water level of each station,analyze relationship between them,and obtain the law of between characteristic tidal level and design water level by correlation analysis method.The results can provide a reference for design water level estimation in future port planning and designing.