Abstract: Based on the bathymetric and hydrological data collected, this paper deals with the seabed erosional and depositional patterns of the ebb-tidal delta in the tidal inlet of Zhanjiang Bay as well as the evolutionary mechanisms of the ebb-tidal delta for the past 50 years. The ebb-tidal delta consists of three components, i.e. the northeast shoal, the southwest shallow, and the deep trough outside the inlet. In the past 50 years, the east edge and the top of the northeast shoal have experienced the process of erosion, while the west and south edge of the shoal remained in siltation. The shoal thus moved westward and expanded southward as a whole; The southwest shoal has been slightly eroded as the deep trough outside the inlet suffered a slight siltation. The evolutionary characteristics of the ebb-tidal delta is influenced by insufficient sediment supply along the coast and human activities nearby, and the silting in the deep trough may be related to the weakening of the tidal dynamics in the tidal inlet caused by reclamation of Zhanjiang Bay; The shallow shoal on north side of the navigating channel has been expanding southward gradually and its impact on back siltation of the channel must be considered.