Coastline from Ba Lat estuary to Lach Giang estuary, Nam Dinh province for many years always place the course of the shoreline, beach, mainly erosion phenomenon and beach erosion led to bank erosion process, sea dykes here. One of the main causes affecting the process of erosion, destructive sea wave in this region. Therefore, the study of wave propagation process for the area under the influence of regional topography and regulation structures on the beach layout is extremely practical significance. The paper presents the results of application of mathematical models to simulate the process of wave propagation, wave-interaction structures in order to assess the mechanism of wave propagation in natural terrain conditions yards and efficiency plans political process, this is a product of the project ''Science-based research and proposing solutions to smbilize the overal coastal Nam Dinh from Ba Lat estuary to Day estuary". The model has been tested by real data wave measurement The test results show that the model can be fully applied in practical calculations to ensure reliability.