Abstract:Based on the data taken from two fishery resource surveys near the sea area of Qushan Island in March and June 2008, this study investigated distributions of Hoplocarida and Decapoda shrimp (simply called “shrimp”) resource density, species composition, richness and diversity (H') ; analyzed the contribution of the dominant species to total shrimp density. Results showed that 18 Decapoda and 1 Hoplocarida species were identified. Among them Alpheus japonicus, Palaemon gravieri and Exopalaemon annandalei were dominant species in March, while Alpheus japonicus was the dominant species in June. Weight density was 840.65 kg/km2 and individual density was 797.34103 ind/km2in March, and 923.52 kg/km2and 647.32103 ind/km2 in June respectively. Both weight and individual distribution showed the same tendency that the densities in the south area were higher than those in the north area. Based on theβ value, we come to the conclusion that the change of shrimp density was closely related with the change of the main dominant species density.