The horizontal and vertical distribution of different phosphorus forms was analyzed in sediment samples collected from Eastern Rushan Bay in August 2003 and the relationship was discussed between the distribution of different phosphorus forms and the bivalve culture. The result showed that the contens of different phosphorus forms in high density cultivating areas were usually higher than those of low density cultivating areas. The vertical distribution of the different phosphorus forms in the cultural areas was complex, their contents were not steady in 1-20cm layer, these were influenced by the bivalve culture. Fluctuation of the contents of Fe-P and Al-P were also influenced by pollution, Or-P was also influenced by activity of phytoplankton. The average percentage of Ex-P、Fe-P、NAIP in TP in the cultural areas was higher than those in the natural areas, De-P and Oc-P were the opposite. The content of Ca-P was the highest, Fe-P and Or-P were the prevalent forms of NAIP. The contents of TP and Or-P had no significant difference between two areas, The content of Fe-P in the cultural areas was higher than that of the natural areas. The contents of three phosphorus forms were general higher than the other areas. Non-bioavailable phosphorus accounted for about 60 percent of TP.