Abstract:To evaluate the relationship between the dynamic changes in the macrobenthic community and environmental factors in Jiaozhou Bay, macrobenthic samples were collected at 12 stations in the winter of 2016. A total of 66 species were identified in the survey area, including 32 species of Annelida, 17 species of Arthropoda, 9 species of Mollusca, 3 species of Echinodermata, 2 species of Chordata, and 1 species each of Nemertinea, Cephalochordata, and Hemichordata. There were 3 dominant species:Branchiostoma belcheri tsingtauense, the dominance of which were 0.02, 0.147, and 0.024, respectively. The average abundance of macrobenthos was 176.7 ind/m2; annelid abundance accounted for 46.01% of the total abundance, arthropod abundance accounted for 17.84% of the total abundance, mollusk abundance accounted for 6.57% of the total abundance, and the abundances of the other phyla accounted for 28.58% of the total abundance. The average biomass was 159.5 g/m2 in the investigated waters; annelid biomass accounted for 6.42% of the total biomass, arthropod biomass accounted for 3.74% of the total biomass, mollusk biomass accounted for 76.56% of the total biomass, and the biomass of the other phyla accounted for 13.27% of the total biomass. The horizontal distribution of abundances showed that the abundance in the nearshore area of Jiaozhou Bay was the highest, followed by those of the area outside the bay and the offshore area of Jiaozhou Bay. The horizontal distribution of biomass showed that the biomass inside Jiaozhou Bay was higher than that outside the bay, in general. The value range of Shannon-Wiener index (') of macrobenthos in the investigated area was 1.19-3.54, with an average value of 2.65; the value range of Margalef's richness index () was 0.91-2.29, with an average value of 1.47; the value range of Pielou's evenness index () was 0.46-1.00, with an average value of 0.87. According to the result of CLUSTER analysis, macrobenthos in the survey area could be divided into 4 groups (S7 and S10 for Group I; S1, S2, S3, S4, S6, S8, S11, and S12 for Group Ⅱ; S5 for Group Ⅲ; and S9 for Group IV). The abundance/biomass curves showed that Group I ('=2.84) and Group Ⅲ ('=3.54) was not disturbed, which was consistent with the evaluation based on the Shannon-Wiener index (') values. BIOENV correlation analysis showed that the best combination that most affected the community structure of macrobenthos was depth + DOC + median diameter + Zn content, with a correlation coefficient () of 0.524. The macrobenthic community is unstable in Jiaozhou Bay owing to human activities, and needs long-term monitoring and evaluation.