Getting information of the interface separating the basement and the sedimentary package is of great importance on hydrocarbon exploration. From the knowledge of this interface we can infer the localization of propitious features of oil and gas accumulation. We present the interpretation of three gravity profiles in Taubaté Basin, located in São Paulo state, and two gravity profiles in Recôncavo Basin, located in Bahia state. We apply the robust polynomial fitting method in gravity data to get the residual Bouguer anomaly resulting from the sedimentary basin. In Taubaté Basin we apply the robust polynomial fitting method in two stage, to mainly remove the effect of great wave length resulting from the crust-mantle interface. For Recôncavo Basin we use the robust polynomial fitting method in Bouguer gravitiy data corrected of the gravity effect due to crust-mantle. We got the interpretation of basement relief delineation, of both basins, using the method of non-linear inversion and smoothness constraint. The gravity interpretation of Taubaté Basin´s basement relief showed an average depth of 895 m, indicating a shallow basement, whereas the gravity interpretation Recôncavo Basin´s basement relief showed an average depth of 6,32 km, indicating a deep basement. Both interpretations are consistent with structural analyses found on literature.
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