The studied area is located in Serra do Mar, Petropolis municipality (RJ), in the southeastern region of Brasil, between the coordinates 22°15'and 22°29' S, and 43°00'and 43°10' W. The aim of this paper is to verify the mineralogical evolution presented in Cambissolos in the Brasilian Classification System (Inceptisols - Soil Taxonomy). This research is part of a project where different types of soils have been studied in distinct local geomorphic features to analyze the relationship between soil, relief and drainage. The studied pedons are in three different local geomorphologic compartments. Profiles 6 is located at south where steep hillslopes and rock walls are observed and the pluviosity is around 2.800mm/year. Profiles 12 and 13 are located at west where the altitudinal variation is not so great (very steeply sloping to precipitous relief) and the pluviosity is around 1.600mm/year. Profiles 10 and 11 are located at north, where the relief is moderately steeply sloping and the pluviosity is about 1.000mm/year. X-ray diffraction (XRD) was taken in clay, silt and sand fractions samples for each horizon of the profiles. Differential Thermal and Termogravimetrical analysis were also taken to evaluate the kaolinite and gibbsite percentages presented in the B horizons. The mineralogy identified in clay fraction it is: kaolinite, gibbsite, vermiculite, illite and goethite. In silt fraction is: quartz, feldspar, goethite, gibbsite, kaolinite, vermiculite and illite, and in the sand fraction, quartz, feldspar, gibbsite and illite/mica. A probable sequence of mineralogical transformation is shown for the profiles: 6, 12 and 13: feldspar»kaolinite»gibbsite; 10 and 11: feldspar»gibbisite, feldspar»kaolinite. In relation to the evolution or the weathering level of the Cambissolos it is possible to define a relative cronosequence: 13<12<6<11<10.