Abstract: Surface sediments from fifteen stations were sampled along the Maolingjiang river estuary (MRE) and Qinjiang river estuary (QRE) areas in the Maowei sea, and analyzed using an improved sequential extraction (SEDEX) method to evaluate the abundance, distribution and potential bioavailable forms of P. Results showed that inorganic P (IP) was the dominant P form, which averagely accounted for 64.4% and 65.9% of total P (TP) pool in surface sediments along the MRE and QRE areas, respectively. Ferric (Fe) bound P (Fe-P) was the dominant IP specie, accounting for 31.2% and 28.1% of sedimentary TP pool, respectively along the MRE and QRE areas. The proportions of other IP species such as the detrital apatite P (De-P), authigenic P (Ca-P) and exchangeable P (Ex-P) were relatively low in surface sediments. Riverine inputs, sediment grain size and sedimentary environment played influential roles on the concentration and distribution of different P forms in the study area. The concentrations of potential bioavailable P (BAP) were 2.95～22.52 μmol/g and 2.67～13.83 μmol/g, respectively, and averagely accounted for 73.9% and 68.8% of TP pool in surface sediments along the MRE and QRE areas, respectively. Thus, surface sediments deposited along the estuarine areas in the Maowei sea show a higher potential for P release into the overlying water.