Base on criteria that were charateristed by the ecological structure and functions of coastal ecosystem degration process, on the impacted causes on ecosysetems assesst degradation the Vietnamese coastal seagrass beds ecosystems were carried out in KC 09.26/06-10 frame. The seagrass bed ecosystems has been covered with arears above 20,000 ha on the coastal waters of Vietnam. They were been degrated in three level (I, II, III) which depend on the different causes that happened in the local areas having different natural ecological, distribution environmental conditions and the social - economical activities... The seagrass beds at the coastal, estuarine and embayment waters in the Northrn of Viet Nam was degrated in the strongest with 80-90 percent per ten years. The degration is lower thqn that at the brackish water poonds. and arounding coastal waters of island. The seagrass beds at the north of central coastal waters (Quang Binh - Quang Nam) in degration is slower than that in the above waters with 60-70 percent per ten years. The seagrass beds at the southern coastal and lagoons waters of Centren was degraed about 50 percent that is lower then above areas. The surrounding coastal seagrass beds of islands in degration is the lowest with 30 percent per ten years (level 1). The rehabitation of some seagrass beds at Tam Giang lagoons when having good managements is rather high (1.5 percent/year/area). This first results is pontential scientific bases for effective management policies in the next time.