G Gravity method is one of the geophysical used to measure variation in earth’s gravity field due to the different between rock mass meetings. This method to determine subsurface structure is gravity method. Gravity data analysis was done by spectral analysis phase aim to produce the depth anomaly zone, the value k (wave number) and determine the width of window (filter). Based on spectrum analysis, this research area has length window 41x41, the depth of residual anomaly that reflects basement Tersier is about 2,1 km, while the depth of regional anomaly is about 17,6 km. For analysing fault structure, the writer used SVD method. Based on result of residual anomaly can be seen that the research area has a relatively westsouthern-southeastern and northsouth anomaly trend patterns that has similar relatively trend of fault structure, fold, and basin deliniation