In Nov. 2005, the macrobenthic community and niche analysis at creeks in three diked tidal flats were studied at Lingkun Island, Wenzhou City, Zhejiang Province. The result revealed 31 species belonging to 19 families, 7 classes and 6 phyla most of which were gastropoda, lamellibranchia, crustacea and polychaeta. In the different habitats of the creeks (the grass flat, the bank of creek and the bottom of the creek), the composition and abundance of the macrobenthic differed. There were 16 species in the grass flat, 21 species in the bank of the creek and 13 species at the bottom of creek. The macrobenthic structure and life forms of the creeks were different in these three habitats, and showed that the creeks changed regularly with the environment factors. In general, the Margalef’s species diversity index: BaC > BoC > GF; the Shannon-Wiener’s index: BaC > Boc > GF; the Pielou’s index: BoC > BaC > GF; the Simpson’s index: GF > BaC > BoC. The analysis of the niche breadth and niche overlap showed that these two were closed related to the distribution and density of the species, which revealed that the niche breadth and the niche overlaps reflect the species distribution, the abundance and the species ability of utilizing the environmental resource. Combined with the data of the four times extraction of the density of macrobenthic species, using the Hierarchical Cluster of between-groups linkage method and the Non-matric Multidimentional Scaling method, these species could be assigned to several groups.
