ABSTRACT
To study the population structure of Decapods in the Intertidal Zone of Bushehr Rocky shores, some random sample collection from four Rocky and rubble shores of Bushehr were done using a 50x50 quadrates sampling unit, in four successive seasons from autumn 2009 to summer 2010. Totally 8 species belonging to 5 family of Decapods were identified and counted. In the whole course of sample collection, the highest frequency rate belongs to Petrolisthes Rufescence species with 51%, pagurus sp. species with 22%, Metapograpsus maculates with 7%, pilimnus sp. with 6.5%, Alpheus lobidens shrimp with 3% and other species with 10.5% ranked next. The results show a drop in frequency and diversity in cold seasons and the most important factor of those changes is temperature changes. Place frequency of Decapods showed that in sites of Lian and Holeileh [C and D Stations] diversity of Decapods is more due to less pollution, less accessibility, and vast and complex bed.