Abstract: We analyzed the Crustaceans stock density, species composition biodiversity index and relationship between community structure and environmental factors based on the data collected by trawl surveys in Zhelin Bay in Feburary (winter), May (spring), August (summer) and November (autumn) in 2013. We altogether captured 53 Crustaceans belonging to 22 Genus, 13 Families and 2 Orders. The stock density ranged from 30.094 kg·km^–2 to 199.048 kg·km^–2. The main dominant Crustaceans were Oratosquilla oratoria, Metapenaeopsis palmensis, Charybdis feriatus and Parapenaeopsis hardwickii, etc.. The diversity index H' ranged from 2.31 to 3.03; the Pielou evenness index J' ranged from 0.55 to 0.80; the Margalef species richness index D ranged from 1.55 to 3.29. ANOSIM analysis, cluster and NMDS analysis show that the Crustacean’s community structure in Zhenlin Bay varied in seasons. The SIMPER analysis reveals that O.oratoria, O.interrupa, et al were typical species, and O.oratoria, Portunus sanguinolentus, et al were discriminating species. The canonical correspondence analysis suggests that the main environmental factors affecting the seasonal variation of Crustaceans community structure in Zhelin Bay are water temperature, pH and dissolved oxygen.