Microbial community diversity and composition are important for the maintenance and functioning of the mangrove ecosystem.In this study,bacterial and archaeal community composition in soils from five locations in the Bamenwan Mangrove Wetland in Hainan,China,were compared using the pyrosequencing technique.The principal component analysis and principal coordinate analysis with UniFrac metrics both showed that the spatial effects on bacterial and archaeal communities were significant.Bacterial community composition among the five samples from different locations presented differences,especially at the order level.Rhizobiales with higher abundance were observed in sediment samples from inner mangrove forests,while higher abundances of Desulfobacterales were in samples from intertidal mudflat and the seaward edge,and higher abundance of Frankiales,Gaiellales and Rhodospirillales in the land sample.For Archaea,Thaumarchaeota and Euryarchaeota dominated in five samples,but the proportion in each samples were different.Similar pattern in dominant archaeal community composition at the order level was presented in the samples from intertidal mudflat and the seaward edge.The dominant archaeal clusters between the samples from two mangrove forests were different,with Soil Crenarchaeotic Group (SCG) and Halobacteriales in sample inside of Bruguiera sexangula forest and SCG,Methanosarcinales and MBGB in sample inside of Xylocarpus mekongensis forest.The dominant archaeal clusters in land sample were special,which dominated by Terrestrial Group and South African Gold Mine Group 1(SAGMCG-1).In summary,spatial variation of the bacterial and archaeal communities in sediments from different locations in Bamenwan Mangrove Wetland was presented.The archaeal community composition of the bulk sediment between two mangrove tree species forests presented more differences than bacterial community,suggesting that mangrove plant had effects on the diversity of microbes in mangrove sediments.