In the South of Vietnam, the provinces including Tien Giang, Ben Tre, Tra Vinh, Soc Trang, Bac Lieu, Ca Mau and Kien Giang belong to the Southwestern culture which contains a legacy of both tangible and intangible cultural heritage. This legacy is variety of forms, rich in value such as Don ca tai tu, the Ong temple/ Whale temple, relics of Ho Chi Minh trail on the sea, the indigenous knowledge, the island and coastal biosphere reserves of Kien Giang province, U Minh Ha National Park and U Minh Thuong National Park, etc. The Vietnamese tourism industry has focused on the developing ecotourism for many years. Through a survey of coastal cultural heritages in the Southwest, this paper concerns about the role of ecotourism and its impact on the protection and promotion of maritime cultural heritage of Vietnam. Based on the reality, the paper will present recommendations to develop the ecotourism and protect the cultural heritage in the Southwestern region of Vietnam.