Abstract:The present paper mainly deals with the phosphorus status of the soils in the suburbs of Shanghai. Two different methods were employed to extract the different forms of phosphorus in the soils. The results obtained showed that inorganic phos-phorus comprised about 90% of the total phosphorus, and of the inerganic phos-phorus calcium phosphate accounted for more than 50%.70-80% of calcium phos-phate took the forms of rock phosphate. Moreever, determination of the transformation of phosphorus in paddy soil by 32P labelling method revealed that, after the application of phosphorus fertilizer to the soils, at first, the majority of phosphorus existed in the form of Al-P, then gradually converted to Fe-P, and finally, most of them were transformed into Ca-P. Through comparative study of extraction of available phosphorus in the soils and through field trials, it proved that Olsen's method is suitable for the soils in Shanghai, This article puts forward some sugestions on the application of phosphorus fertiliters to the soil in the suburbs of Shanghai.