The aim of this study was determination of diversity, dominance and species richness of intertidal zone crabs of coastal field of Bushehr seaport. 9 stations were selected for sampling in the inter-tidal zone and sampling bed sediments was done in both warm (August 2015) and cold (December 2015) seasons using Quadrate (25×25 cm) randomly. Samples were preserved by using 10% buffered formalin and transported to the laboratory and counted and identified. More over physicochemical properties of water such as temperature, pH, dissolved oxygen (DO) and water salinity were also measured in each station. Diversity index was investigated using Shannon-Weaver formula, dominancy index was investigated using Simpson formula, and species richness was investigated using Margalof formula. The identified samples were totally 13 species from 7 families and 1 order. The most frequent identified families in seasons were Grapsidae , Porcellanidae  and Xanthidae. According to the results of ANOVA, there were significant differences between frequency changes of crabs in all stations (P<0.05), but there were no significant differences between frequency changes in both summer and winter seasons (P>0.05). Also results of this study indicate that the most diversity rate (1.916) was in station 3 and warm season, the most species richness rate (4.454) was in station 3 and warm season and the most dominancy rate (1.000) was in station 1, 2, 9 and warm season. At the end of study, we can conclude that diversity of inter-tidal zone crabs in Bushehr seaport coastline was low.