One of the main concerns of human being is producing enough energy for living while this energy is achieved through the sources with low cost of production, high potential and low negative environmental impact. One of these clean energy sources is geothermal energy which is ideal because of both low cost of production and being environmentally sustainable. Due to the amount of heat extracted from geothermal energy sources this energy is used as heat source in home or in industry, greenhouses, agriculture, and the electricity is used. "The benefits of geothermal resources available" refers to that part of the utilization of geothermal resources which is available in a particular future (less than a hundred year). Usually when talking about the geothermal resources, our main point is that it is better to make it part of the geothermal resources "portion of available resources" call. With increasing awareness of the harmful effects of burning fossil fuels on the environment, interest in clean and renewable energy such as geothermal energy resources around the world expands. The first geothermal power plant in the province of Ardabil with the ultimate capacity of over 250 MW in Sabalan mountain range came into operation in 1385. According to researches there is the possibility of extending the plants to the other susceptible areas such as slopes of Mount Sahand, Sabalan and Taftan. With regard to existence of the volcanic regions in the country and the possibility of geothermal resources in East Azerbaijan province, a preliminary exploration study is carried out on the 1:100,000 geological map of Osku that encompasses the main part of Sahand mountain. Geographic Information System (GIS) and modern techniques for representing spatial data are widely used in practice such as geology and geo-modeling processes. In addition application of data processing methods like statistical analysis have been improved the GIS capability. Employing the geographic information system (GIS), as a tool in the processing and interpretation of the data, is quite helpful especially in the exploration, appraisal, and reduction of human errors in the processes. The advantage of this approach is the exploration of mineral resources through exploration methods for gathering and fusing the relevant information from different layers. Bonham Carter and others (1988), Agterberg (1989), Katz (1991), Cheung and others (1992) have worked on with GIS system to determine suitable areas for mineralization and decide on the next steps in their exploration. GIS exploration of geothermal resources already has been used successfully used in Mexico by Prvl Ldsma (1999), Nevada in America by Kvlbaf (2002) and in Turkey and Japan. In this research different exploration data including lithological and structural information, hot springs positions, and geophysical data including airborne magnetic, gravity and seismic surveys, regional stream sediment geochemical data and remote sensing data (ASTER) are collected and integrated in GIS system for potential mapping and locating the high priority areas for further exploration activities. Fuzzy logic and weighted overlay approaches have been taken into account for resource mapping.