Tien Chau estuary is located in the downstream area o f Ky Lo river, empties into the East Sea through Xuan Dai bay, and plays an important role in developing the marine economy and fishing o f Phu Yen province in general, and Dry An district in particular. In recent years, the sedimentation problems at the Den Chau estuary have significantly been affecting the fishing fleet o f the Div An district and surrounding areas. This paper describes the morphological evolution, o f the Den Chau estuary based on the analysis o f remote sensing images. The correlation between the morphological evolution o f the Den Chau estuary with the key factors including flooding, waves, flow fields induced by waves, tides, and storms has been clarified through the numerical results o f the state-of-the-art DelftI D model. These are crucial scientific knowledge required to propose suitable solutions to stabilize the morphology o f the Den Chau estuary in the future.