Fractionation of phosphorus was made on ten samples (A1 horizon) of different types of soils, of the State of São Paulo, according to the method of Chang and Jackson. Red Latosols (Latossolos Roxos) showed for all forms higher levels of phosphorus than the o other Latosols studied except for the Al-phosphate. Terra Roxa Estruturada had a remarkable content of Ca-phosphate, being similar in other characteristics to the Latosols "Roxos". The different Podzolic Soils were uniform in phosphorus content. A predominance of occluded Fe-phosphate, about four times greater than the active Fe-phosphate, was observed. A comparison between the Latossolo Roxo - Terra Roxa Estruturada and the other samples showed that the former were, in all forms of phosphorus, richer than the latter, especially Ca-phosphate. In the Terra Roxa Estruturada, the Ca-phosphate level reaches 1.90 meq of PO4-3 per 100 g of soil (about 200 ppm of P). Organic P varied between 0.03 and 1.37 meq of P0(4)-3 per 100 g of soil. Considering the organic P as a percentage of the total P, a variation was noted between 9.8 and 31.3%. The soils studied showed the following P. fractions, in decreasing order of importance: occluded Fe-phosphate, Fe-phosphate, organic phosphate, Ca-phosphate and Al-phosphate.