Abstract: Analyses of the velocity data at No.14 Station of Chengjiawu channel for two tidal periods show that the ebb current is strong and that the flood current is weak. The tidal current characteristics, velocity's elliptic distribution of each layer, distribution of mean velocity of tidal current and characteristics of the residual current at the station are analyzed. The vertical distribution of tidal current velocity at the station is fitted and a calculation formula for Chengjiawu channel is then given.