T The location of the research in the field is at Silangkitang, North Tapanuli Regency,North Sumatra Province. The purpose of this research is to create a conceptual model of thesystem has constantly strived research areas, and upflow zone and outflows based ongeochemical methods. The first method is groundwater geochemical method that includesthe ion balance, water types, the origin of the water, water, geoindikator geothermometerand water. The second method is gas geochemical method that covers the origin of the gasgeothermometer and gas geoindicator. The third is isotop geochemical method namely fluidsources. Research areas are included into high relief liquid-dominated system, and areincluded the volcanic hidrothermal system. Based on the reservoir temperature, researchareas including into the system has constantly strived high temperatures with reservoirtemperature range between 250ºC up to 300ºC. Based on the interpretation of the geologicaland geochemical data, upflow areas on the research area is located at the G1, G2, G3, G4and G5 which is located in the middle of the research area, while the outflows are locatedtoward the southeast direction of research areas