Vietnam is a coastal country with a coastline stretching more than 3,260 km. Marine resources are important for the development of Vietnam. In Vietnamese seas, there are about 20 typical ecosystems spreading over 1 million square kilometers in the East Sea consisting of mangrove forests, coral reefs, lagoons, seagrasses in intertidal areas and estuaries, and living species in 155,000 hectares, 1,300 square kilometers, 500 square kilometers, 16,000 hectares, and 11,000 living species, respectively. At present, the impact of climate change, socio-economic development, and environmental pollution are considered as the main causes of degradation of Vietnam’s marine ecosystems. This paper presents and discusses the pressure of socio-economic activities including industry, tourism, marine transportation and services, aquaculture and fishery on marine ecosystems. In Vietnam, compared to the early 2000s a total of 12% of coral reefs, and 48% of other coral reefs are vulnerable to degradation. So far, about 100 species of marine life in Vietnam are at risk of being threatened due to over-exploitation and fishing. The seagrass-bed ecosystem is currently being degraded with only over 5,580 ha remaining. In some areas, such as Cat Ba, Ha Long, and Quang Nam, seagrass beds have almost no chance to recover naturally due to serious impacts from tourism and aquaculture activities. From the findings, orientations that aim at effective management and protection of marine ecosystems to cope with adverse impacts of anthropogenic activities, climate change, and the pressure of socioeconomic development were proposed.