Water samples were collected for phosphorus (P) analysis in the rivers polluted with farming (Type-A), fishery (Type-B) and domestic sewage (Type-C) in Taihu Basin, China. The results show that the total phosphorus (TP), the total dissolved phosphorus (TDP) and the soluble reactive phosphorus (SRP) are slightly higher for Type-B river than Type-A river, but much lower than Type-C river. On the contrary, enzymatically hydrolysable phosphorus (EHP) in Type-A river is the highest with a maximum value of 0.11 mg L^-1 in high-water period, and is the lowest for Type-C. Laboratory analysis reveals that mineralization rate of organophosphorus is significantly higher for Type-A and –B rivers than that for Type-C, especially in high-water period with a maximum value of 1.437 nmol L^-1 min^-1. EHP is found to be positively related to mineralization rate, and organo-phosphorus has a regeneration period of 3～7 days in Type-A and -B rivers versus the 9.1 days in Type-C river. Overall, the distribution and mineralization rate of P are river-type dependent. The major TP contributed from domestic sewage, while the phosphorus contributed from farming and fishery is more readily available to plants in Taihu Lake.