This paper characterizes the distribution of phosphorus fractions and matrix-bound phosphine (MBP) in coastal surface sediments of the Southwest Yellow Sea from 2006 to 2007. Total phosphorus (TP), inorganic phosphorus (IP) and organic phosphorus (OP) concentrations (mg kg(-1)) range from 278 +/- 3 to 768 +/- 15, 160 +/- 1 to 653 +/- 27, and 3.42+/- 0.05 to 267 +/- 22, respectively. MBP is a small portion of TP with values of 0.69 +/- 0.06 to 179 +/- 29 ng kg(-1). Phosphorus fractions and MBP are influenced strongly by riverine input and hydrodynamic conditions. High TP and MBP are found in the old Yellow River mouth and the Yangtze River mouth. OP and MBP are strongly negatively correlated to mean particle size. Significant positive correlations are found between MBP and IP and OM, suggesting that MBP production may be the microbially intermediated transformation of IP.