Abstract:Based on the observation of the current at several stations conducted synchronically in winter and summer respectively in Lianyungang nearshore area, we analyze the variation characteristics of tidal current, and the type, motion form, maximum velocity and direction of tidal current with the tidal current elliptic factors calculated by the quasi-harmonic method. The results show that the velocity and duration of flood current and ebb current are different. The tidal current is classified as regular semidiurnal tidal current in shallow water. The tidal current is rectilinear current in the nearshore area. With increasing depth, the rotating flow is apparent, and most directions are counter-clockwise. The variation of the maximum velocity and direction are obvious in different seasons.