Abstract: To reveal the community structure and diversity of intertidal zone molluscs in the Nanji Islands, the quantitative and qualitative investigation of Nanji Island intertidal seven sections were studied for four times in November 2013 and February, May, August 2014.Traditional diversity analysis, community and non-metric multi-dimensional cluster, Abundance Biomass Comparison curve analysis method of combining measures were used to research community structure and diversity of molluscs.The results showed that:(1)63 molluscss species were identified belonging to 3 classes, 13 orders, 34 families and 52 genuses.In spring, summer, autumn and winter, 48 kinds, 48 kinds, 45 kinds, 41 kinds of molluscs were identified, respectively.Dominance of species in different seasons is different, and there are four kinds in spring, four in summer, five in autumn and three in winter.Septifer virgatus is the largest dominance of the species researched.(2)Seasonal differences in changes in community structure consisting of molluscs is notable, and spring, summer, autumn, winter group within similarity were 30.77%, 24.66%, 19.58%, 39.01%, respectively.In the spring-summer and summer-autumn, autumn-winter, winter-spring, the average dissimilarity were 39.82%, 39.00%, 47.64%, 48.02%, respectively.(3)Molluscs Shannon-Wiener diversity index (H') in the fourth quarter average was winter(1.73) > spring(1.69) > summer(1.58) > autumn (1.40).(4)With cluster analysis and non-metric multidimensional scaling(NMDS) analysis, the intertidal zone molluscs community can be divided into two groups, mainly due to the different habitats.(5)Abundance Biomass Comparison curve showed that spring, autumn, winter community structure did not suffer significant interference, the summer disturbed moderate intensity.