Abstract: In this study, species composition, stocks density and diversity index were compared and analyzed based on crab samples collected from Xiamen sea areas in seasons from 2006 to 2007 and 2016 to 2017. Results showed that, species composition of crabs in Xiamen sea areas had significantly changes, with a species replacement as high as 55.32%. Along with the presence of some species such as Xanthidae, Grapsidae and Dorippidae, and the absence of some species in Portunidaeand and Goneplacidae, the crab abundance decreased. However, the changes of evenness, diversity index and density were insignificant. The community structure of crabs became simplified. The average weight of individual crabs had increased during the study period, and there was a certain degree of Scylla paramamosain stock recovery during surveys, particularly with a significant increase of crab density in autumn. This study recommends strengthening the management and restoration of marine habitat with measurement such as fishing bans.