We evaluated the community structure and diversity of invertebrates in the northern region of China Sea using data collected from bottom trawl surveys in May and August 2010. We collected a total of 32 invertebrate species, including 15 species of shrimp, 10 species of crab, and 7 species of squid. Shrimps were dominant in Bohai Sea, accounting for 86.57% of the biomass and 96.55% of individuals in May and 46.16% of the biomass and 80.85% of individuals in August. In contrast, the north region of the Yellow Sea was dominated by crabs in May (s). We quantified the ecological dominance of a species using an index of relative importance (IRI). The dominant species changed between seasons and regions. We calculated three diversity indexes to analyze the diversity of invertebrates: the species abundance index (), and the species evenness index (Bohai Sea than in the northern region of the Yellow sea. The Bray-Curtis , a measure of the similarity of the invertebrate community in the two regions, was 0.315 in May and 0.297 in August. The season transformation index (AI) and the transfer index (MI) suggested that some species migrated from Bohai Sea.