This article has provided the initial information about the coral eating snail populations (Drupella spp.) In Cat Ba. Have identified three species of coral eating snails of the genus Drupella distribution in Cat Ba: Drupella com us, Drupella rugosa, Drupell. margariticola. Also identified is the average density, distribution with depth and microhabitat use selection of the coral eating snails (Dupella spp.) in the study area. This information is very important scientific basis for subsequent research in order to find out the satirical approach management and use sustainable coral reefs resource in Vietnam in the future.