This study was conducted to reinforce the hypothesis that ecotourism in Quang Loi commune’s lagoon created differences in income and lagoon resource protection of different beneficiary groups. Data was collected through secondary sources, 3 key informant interviews and interviews of 62 households in three household groups: tourism service, fishing, and aquaculture households. The results reveal that ecotourism services in Quang Loi commune started in 2010 and thrive since 2017, relying on the advantages of the local natural resources. Local community organized and provided tourism services such as: sightseeing on the lagoon, fishing experience, dining and accommodation, and some other services. By joining such services, labors in ecotourism service households earned 39.07 million VND/ year, which significant contributed to improve household’s income. Ecotourism service households, therefore, had higher income than that of fishing group and aquaculture group (85.15 compared to 72.29 and 60 million VND, respectively; p value < 0.05). The lagoon environmental protection activities such as: lagoon night patrol, waste collection, propaganda and advocating for lagoon environmental protection, etc. were paid more attention by the local community since the development of ecotourism. Similarly, there was a significant higher participation time of tourism service households in the above activities in comparison with the rest groups (p value < 0.05). The lagoon environment and resources was assessed to be improved by local residents. This result implicates that ecotourism development is a suitable strategy to improve the local people’s livelihood and Tam Giang lagoon resources protection currently.