The tidal numerical model of Longqiwan port is established based on the measured hydrologic data,and the research on water particle motion and exchange is carried out for different planning schemes. Research shows that water particle motion change at Longqiwan port’s east side is not obvious in different planning schemes. From water particle motion effect perspective,it is not significant effect to improve water exchange from different planning schemes,especially it will increase the pollution of coastal location in offshore schemes. Tidal inlet does not play significantly role in improving the water exchange for the harbor. Overall,the original plan is more suitable for the current planning requirements.