Objectives of the study were to explore forms, quantities and distribution of soil phophorus in profile of paddy soil as affected by different fertilization patterns in a long-term experiment under a rice wheat (or rape) cropping system, and to evaluate potential effects of transformat ion and downward transport of phosphorus on environment.The experiment that has been carrying on since 1980 on a permeable paddy soil (huang ni tu), is designed to have 14 treatments with 3 replicates.Soil samples were collected from the top soil (0~15 cm) and then layers 5 cm apart till 1 m in depth in November 2002.Significant P accumulation was found at the depth of 25 cm for all P treatments but Treatment M_NPK (Manure+fertilizer N+fertilizer P+fertil izer K) where it was detected at the depth of 30 cm.Inorganic P (I-P) concentrations increased significantly in the soil layer of 0~25 cm for most P treatments.Ca₂-P moved beneath 30 cm in soil depth, Al-P, Fe-P and Occluded-P (Oc-P) to 25 cm in depth, and Ca₈-P to 20 cm in depth.Ca₁₀-P contents increased significantly only in treatments with fert ilizer P application, showing manure P keeps available longer than fertilizer P.Changes in O-P were smaller than I-P in range.Merely in the plots with manure plus fert ilizer P or with fert ilizer P and K, the organic P (O-P) concentration in the top soils (0~15 cm) increased significantly.Long term of P application exceeding P removal by crops were not economical because more inactive Oc-P and Ca₁₀-P accumulated, and led to P accumulation in the top soil and hence the potential of P loss via surface runoff and leaching that would threaten the quality of surface water and groundwater.