Abstract：Yangshan port is a China's major port and is building into an international shipping center. Docking of foreign vessels puts the Yangshan Port in a high risk of biological invasion. At the same time, the attachment of the fouling organisms in large numbers seriously affects the port facilities. In order to explore the diversity condition and development trend of fouling organisms in Yangshan Port, the community structure and the diversity of fouling organisms were studied by an asystematic scheme of quantitative quadrat sampling in different intertidal areas of Yangshan Port on May 2010. 17 species of fouling organisms were sampled. The dominant species were Amphibalanus reticulates and Ostrea cucullata. Density, biomass, community structure and diversity see significant difference in different intertidal areas. Species richness, density and biomass show an increasing tendency with the rising of the intertidal area. However, the evenness shows a decreasing tendency. The biodiversity index varies in the following manner: middle tidal zone>low tidal zone>high tidal zone. The coverage data of live fouling organisms in Yangshan Island are obtained. It is shown that the highest diversity occurs at the coverage of 30%~40% range of fouling organisms, and this result supports the intermediate disturbance hypothesis in all three diversity indices. Coverage is the basic parameter widely available for most observations or monitoring programs. The good qualitative characteristics of coverage provide a powerful tool for theoretical, experimental and modeling studies of fouling organisms in response to the disturbance.