Based on the hourly data of 4 representative stations on the Chinese coastal areas from tidal table，all high tides（method 1）and one higher tide per day（method 2）are selected to calculate the tide riding water levels of different assurance rates，and the influence of the two methods on the engineering application is analyzed. The results show that method 2 can raise the tide riding water level and save the project cost，but it can shorten the navigation window period and increase the waiting time of ships，bringing inconvenience to the project running and operation. This influence is not obvious to the regular semidiurnal tide，but very obvious to the other tide types，especially to the irregular diurnal tide. For the engineering application of the irregular semidiurnal tide and the diurnal tide port area，the appropriate tide level can be selected comprehensively after detail analyses of the two methods combining with the engineering investment and the ship arrival frequency，which can not only meet the engineering application but also save the project cost.