Abstract: Based on the synchronous observed current data of seven stations in the east side of Liaodong bay in autumn, we analyzed and compared the characteristics of tidal and residual current by means of harmonic analysis.The results showed that:(1)The dominant tidal current constituent was M₂ with the maximum speed ranging from 35.8 cm/s to 69.8 cm/s, and the major axis directions of M₂ and K₁ tidal current were basically consistent with the shoreline.(2)The regular semi-diurnal tidal current in the north of Liaodong bay was obvious, while it was mainly irregular in the central and south of Liaodong bay.The north part of Liaodong bay and the south part of Jinpu bay mouth belong to the strong tidal zone, while the tidal current in the north and middle parts of Jinpu bay mouth were relatively weak.Furthermore, the directions of maximum possible tidal current were parallel to the coastline approximately.(3)The residual current was weak in the eastern area of Liaodong bay, and was characterized by the southward migration along the coastal line, therefore the long-term transport effects of pollutants could not be ignored.