Abstract: A beach nourishment project will be conducted at the Laohushi beach of Qinhuangdao. To better understand the impact of the project to the tidal field, a 2D tidal field model was setup based on MIKE21 model. The model was verified by comparison of the simulated and measured data of tidal level, velocity and direction. The verified model is adopted to simulate the tidal fields after the project with the same computational parameters and open boundary conditions. The comparison of the tidal flow before and after the project shows that the impact of the sandbars to the tidal current is limited in the region around the sandbars, and negligible in the region 500 m far from them. The tidal current in the Laohushi beach after the project is still very weak to move the sands away from the beach.