Concentrations of total phosphorus (TP), their fractions and the bio-available phosphorus(BAP) in the surface sediments From three different regions of Lake Taihu are investigated. In addition, the potential release capacify of P from the surface sediment and their sources were discussed. The concentrations of TP, P fractions an BAP are coincided very well with their trophic states. The concentrations of organic P in the sediments have a good relationship with organic matter and moisture content. BAP is mainly from Fe bound P(Fe-P) and Ca hound P(Ca~P), which show the highest potential risk of release.