Using the measured tidal data of the entrance channel of Toumen Port,the distribution and movement characteristics of tidal currents are studied through quasi harmonic analysis.The results showed that：1) The maximum flow velocity of the entrance channel is 111 cm/s.The flow velocity of the leading section of Toumen Island is slightly higher than that of the offshore section,and the flow velocity of the spring tide is greater than that of the neap tide.The vertical distribution of flow velocity gradually decreased from the surface to the middle and bottom layers.2)The main factor affecting the sea area of the entrance channel is M2-point tidal current,which is a regular semi diurnal shallow sea tidal current.The motion characteristic of tidal current is reciprocating flow,and the tidal ellipse is relatively flat,the maximum flow rate may be between 80-145 cm/s.3) The residual flow value is not significant,with a maximum value of 9.2 cm/s.Overall,the residual flow in the offshore segment is slightly higher than that in the forward segment of Toumen Port.The direction of residual current in the forward section of Toumen Port points towards the ebb tide direction,while the direction of residual current in the offshore section points towards the rising tide direction.