Abstract: Biological diversity, structural characteristics and habitat density of the benthos in the intertidal zone near Lianyungang Tianwan Nuclear Power Plant were studied, according to the seasonal ecological surveys conducted in 2008. In ecological aspects, the benthic biomass and the density of Bsection (fish culture zones: 42.32 g·m^-2 and 71.83 ind·m^-2) were higher than those of A Division (natural habitat Beach: 11.24 g·m^-2 and 63.67 ind·m^-2). Community similarity data had shown that marine engineering may make benthos communities reduce the degree of differentiation of the area between the various habitats. The diversity index for the 4 seasons is 1.72, 1.20, 1.68 and 0.84, respectively. The seasonal changes in community diversity displayed in the most polluted winter probably had a relationship with the disturbance of marine engineering activities, which was likely to lead to the changes in the structure of ecological communities, or even the destruction of habitat and loss of biological diversity. Overall, the community structure was not very stable in the intertidal benthic animals near the Tianwan nuclear power plant. It cannot be immediately concluded that nuclear power plant engineering activities were related to the extent of the impact. We need to continue to investigate the biological resources of the area to monitor the situation, forming a long-term and effective monitoring mechanism.