Surface sediments were collected from the Xiamen Gulf in March 2010. The sediments were analyzed with modified SEDEX (sequential extraction and separation analysis method) to obtain Ads-P (absorbed phosphorus), Fe-P (iron-bound phosphorus), Ca-P (phosphate bound onto CaCO₃), De-P (detritus phosphorus), and OP (organic phosphorus). Along with environmental parameters of sediments, the geochemistry characters of phosphorus were discussed．The mean contents of Ads-P, Fe-P, De-P, Ca-P, OP, and TP (total phosphorus) were 9.80, 48.69, 14.07, 136.89, 91.97, and 401.41 μg?g^-1, respectively. The results showed that TP was weakly influenced by terrestrial input, and De-P, OP and Fe-P were mainly influenced by terrestrial input. Ads-P and Ca-P were mainly from biogeochemical processes of the sea area. Ca-P, De-P and OP with heavy metals (Cu, Pb, Cd, and As) possessed chemical coupling, and might have similar geochemical behavior in the deposition process.