Abstarct: One of the environmental consequences of mining activities is generation of large amounts of solid and liquid waste during the extraction and processing of ore. Some of these materials contain harmful substances and high concentrations of mextals and heavy mextals. In the mining industry, tailings dam is regarded as the most suitable method for waste disposal. Selection of an appropriate site for tailings dams is a major challenging problem in the management of waste materials. In the past dams site selection process was baxsed on economic considerations and to facilitate the operations. But in the current situation and the critical importance of environmental considerations, tailings dam site selection process is complex. There are many factors in the making decision to choose the most appropriate site for disposal of mining wastes. The most important criteria are: the distance from processing factories and residential areas and agricultural, region's mineral potential, faults, rivers and roads, land use, geology, soil science, hydrology and hydrogeology and other factors. These factors must be rendered in geographic information system (GIS) and the analyzing by hierarchy process (AHP) for locating laxyers of the tailings dam of sangan iron mine complex. So that all information laxyers criteria using GIS software was classified. Then to weight the data laxyer of AHP and Expert choice software was used. Total area intended for site selection of about 370 square kilometers was that after the zoning, approximately 59.5 square kilometers within the highly improper, inappropriate in the range of 86.5 square kilometers, 111 square kilometers in the middle range, 99 square kilometers within a reasonable range and 20 square kilometers in the area were very good. The area of approximately 16 square kilometers in the southern area designated for construction of the tailings dam was appropriate.