Abstarct: In recent years, Geological storage of CO2 is the main way to reduce this greenhouse gas content in the atmosphere. CO2 can be stored in salin structures, depleted gas and oil reservoir and unminable coal seams. According to this thesis, distance between source of emission to storage sites is the main criteria for choosing best storage sites. Then caprock thickness and unfaulting caprock are put in the second ranked. Storage capacity is placed in the next ranked and other criteria such as permeability, reservoir thickness, pressure,porosity and depth are put in the last ranked. In this thesis according to available data first, we evaluate ten anticlines in the west of iran and then we rank these sites by using Analytical Hierarchy Process (AHP). Result shows that Anjir is the best sites for storing CO2. Deyreh, Govar and Darabadam are placed in second ranked. At the end, according to unsutaible criteria of Veyzenhar structure, this ancline is place at the last ranked.