Abstarct: Use of geophysical methods. Measuring the physical properties of subsurface rocks is a good way to investigate subsurface structures and discover buried reserves in the baxsement, such as petroleum, gas, water and minerals. The gravity method because of simplicity to survey, interpret and cost-effectively, including the most widely used geophysical methods used for introductory explorations. Due to the fact that the high anomalies are due to the difference in the density of the floors and their non-homogeneity, the method of gravimetry is used to study the gravity anomalies. Sodium sulfate is a practical mineral that forms in evaporative environments. The Garmab sodium sulfate range is located in the south east of Semnan city. Due to the fact that sodium sulfate has a significant density difference with surrounding sedimentary laxyers and its density is higher than surrounding rocks, the method of gravimetry was used. The Gramab Mining area gravity data of Semnan was measured using CG5 gravity device in several profiles and then necessary corrections for the events done. In this study, optimum heights were estimated for the upward continuations. For this purpose, upward continuation applied to different heights on the Bouguer map, and finally an optimal height was estimated. In order to make a better comparison for the separation of the anomalies, the trend method was also used for separation and compared with the upward continuation residual anomaly maps, the depth of the anomalies was estimated using the Euler method, and also using the Geosoft software, two-dimensional models were modeled and the shape of the anomalies was estimated. The depth of the mass was about 30 to 60 meters and four points were proposed for drilling.