Phosphorus content of surface sediments (0～ 1 cm) sampled by multicorer in specified area (31°00′～32°00′N, 122°30′～124°00′E) outside of the Changjiang Estuary in October 1997 and May 1998 respectively is analyzed. Combined with the data of phosphorus concentration in seawaters, grain size and chemical composition as well as the isotopic sedimentary rate of surface sediment and etc., it is recognized that seasonal variability of different water massea could be sensitively recorded in sediments.Distribution pattern of phosphorous in surface sediment in the area is probably both controlled by the Changjiang River diluted water mass and the Huanghai Sea and the East China Sea mixed water mass.Retransportation and resedimentation perhaps do actively happen in the study region that could make resuspended sediments release pollutants as phosphorus into seawater and have significant impacts on marine ecosystem, although it is indicated that at least some of phosphorus in sediments exists in immobile or inorganic forms.