There is gravity measurement that is supported by magnetic measurement in Sangon to identify porphyry body and geological structure as low sulfidation epithermal system control. The survey area is 6.4 x 5.6 km for gravity method and 2.5 x 1.2 km for the magnetic method. The value of gravity anomaly after flat plane reduction processing is 122-142 mGal which is positive anomaly located in the north-eastern area and negative anomaly to 82- 102 mGal located in the south-western area. Whereas the magnetic residual anomaly is - 800-1300nT.Conducted 2.5 D modelling of gravity method that is based on local anomaly slice. The result of 2.5D modelling show that an intrusion body interpreted as Dacite intrusion as host rock which plays a role as a heat source of the mineralization system. The density of Dacite is 2.70 gr/cm3. The result of gravity modelling has a correlation with the result of magnetic modelling. Based on magnetic modelling, the intrusion body is located in the south-west.