Keywords: 
• Seagrass meadows /
• macrobenthos /
• diversity

Abstract: The macrobenthos in the Xincun Bay of Lingshui County,Hainan,China were investigated to analyze the relationship between their structure and the seagrass habitats. The result showed that macrobenthos in the Xincun Bay were mainly composed of bivalves,accounting for 43% of the total,followed by gastropods accounting for 26% of the total. The main species did not vary significantly with season,and more species were generally observed in summer and autumn,but less in winter and spring. The dominant species were Batillaris zonalis in spring,Arenicda cristata in summer and autumn,and Dasybranchus caducus in winter. Observation of the biomass variation in the whole year showed that the biomass changed greater in summer and autumn than in spring and winter,and tended to decline from the seagrass region to the outward. The density and biomass of macrobenthos communities in different seagrass habitats were different,and the density,biomass and biodiversity index H’ of Thalassia hemperichii were the highest. Biodiversity and evenness index of macrobenthos in the seagrass habitats were higher in summer and autumn,and lower in spring and winter. Cluster analysis indicated that macrobenthos communities were similar in the habitats of Halodule uninervis,Halophila ovalis and Halophila minor of the sea area under study.