Gravity method is a method used to find the difference of gravity value from one point to another in a place caused by mass distribution which is below the surface of research area. Basement identification of complete Bouguer anomaly data has been done in the Timor Basin with geographical position 9.40 LS – 10.40 LS dan 123.50 BT – 125.40 BT. The identification of the basement under the Timor Basin is based on gravity field anomaly data. The gravity field anomaly data used in the research is the result of measurement of Geodetic Satellite and European Remote Sensing Satellite which has been corrected to free air correction. Based on the inversion, the overall average density from the first layer to the tenth layer 2.662 . Timor Basin which is a place of accumulation of sediment and has a basement which is a type of metamorphic rocks from within 3.86 km to 20 km strong and is not pass the water hence this basin has the potential of a trap of natural energy sources in the form of oil and gas. Keywords: Gravity, Basement, Basin, complete Bouguer anomaly, density, modeling.