Abstract: We explored the macrobenthos community in nine intertidal sections around Dongxilian Island, Cheniushan Island, Dashan Island and Pingshan Island in northern Jiangsu in spring and autumn of 2007.127 species were found in this area, 35.43% of which are algae while 28.35% are mollusk and 16.14% are crustacean. Fifty-six species were found in the embayed waters, among which the main species are mollusk. Ninety-two species were found in the open sea and algae are the main species. The dominant species are Chthamalus withersi, Mytilus coruscus and Alectryonella plicatula. The average biomass is 4 150.42 g · m^-2, with mollusk being the highest (81.89%); the average density is 17 642 ind · m^-2 and crustacean is the highest (76.91%).The biomass in the open sea is higher than that in the embayed waters, and the order of tidal biomass from high to low is low tidal area > middle tidal area > high tidal area. The biomass in autumn is higher than that in spring.