Abstract: According to the survey data of organisms attached on concrete and iron reefs in September, 2008 in Yangmeikeng, Shenzhen, the compositions of common species and the characteristics of the community structure were studied based on principal components analysis, the hierarchical cluster analysis and multidimensional scaling. The results showed that the common species were composed of Balanus trigonus, Molgula manhattensis, Perna viridis, Cirriformia tentaculata, Musculus mirandus, Engina pulchra, Ophiura sp., Brachidontes variabilis, Opisthosyllis brunnea, Iodictyum axillare, Bugula neritina, Cerithidea cingulata, Modiolus barbatu, Trapezium liratum, Thelepus sp. and Styela canopus.Organisms both attached in upper layer and lower layer of concrete and iron reefs generally clustered together, but those in middle layer did not.