The main soil types of the State of São Paulo, Brazil, were studied during the last 15 years and their general description is presented in this paper. Over 80,000 km of field excursions were made in order to collect approximately 4,000 rock samples, 700 profiles from depths varying from 1.5 to 5.0 m, 20,000 shallow samples and about 6,000 photographs. The soil types studiel cover an area of 24,700,000 ha, located between the latitudes 19° 50' and 25° 10' South, and the longitudes 44° 10' and 53° 10' West (Greenwich), the altitude varying from 3m to 1,700 m above sea level. For this area the temperature range in the dry winter season (May to July) is from 0° to 25°C and in the rainy summer months (November to February), from 18° to 30°C. The rainfail varies from 2,000 to 3,000 mm (along the cost) and from 1,000 to 1,800 mm in the plateau. The following ten main soil types were described : massapé salmourão, devoniano, glacial, corumbataí, arenito Botucatú, roxa legítima, arenito Baurú, terciário, baixadas, and roxa misturada, and their locations are given in fig. 3. For the ten soil types, determination of physical and chemical properties were made and presented in tables 1 to 14. General information is also given on the specific area, geological origin, topography, native vegetation, and main crops grown in each one of the soils studied.