Abstarct: Chahshirin copper deposit is located in the northern margin of the structural-sedimentary zone of Central Iran below the Sabzevar zone and the western part of the Troud Chahshirin volcanic-sedimentary belt. This area is located 110 km south of Damghan city in Semnan province. The volcanic rocks of the area include andesite, basalt and pyroclastic rocks such as lithic tuff and agglomerates of Eocene age. Alteration zones observed in this area include carbonate, silica, argillite, sericite and iron oxide alterations. Field observations and mineralography studies reveal that the mineralization in the Chah shirin area often oc- curred as vein- veinlet, disseminated, open space filling and exolution occurred in the host rocks of andesite, basaltic and tuffs.Effective factors controlling mineralization in the area joints, gaps and faults with northeast- southwest trend. The minerals forming Chahshirin copper deposit occurred in three stages: hypogene (bornite, chalcopyrite), reductive su- pergene (chalcocite, Covellite, digenite) and oxide supergene (malachite, azurite, Oxide and hydroxide iron). The tailings of the study area are quartz and calcite. baxsed on geo- chemical data, the volcanic rocks in the area have calc-alkaline nature in terms of chemical composition and in terms of tectonomagmatic is related to subduction zone.The volcanic rocks of the area show a normal enrichment of small LILE elements such as Rb, K de- pletion of larg HFSE elements such as Nb and Ti according to the normalizing diagrms relative to the chondrite and primary mantle, which is characteristic of magmas. Derived from the mantle in the subduction zone. Geochemical studies indicate that copper has only relative correlation with silver. Since silver has not founded as an indepnded crystalline phase. The results of fluid inclusion studies on the calcite, frequency homogeneous tem- perature averaging between 100 and 110 ° C and salinity with an average of 8 by weight equivalent to Nacl and due to the lack of evidence, boiling shows a depth of more than 150 meters. This system was related to evolution of mineralizing hydrothermal fluids and their mixing with cold and low salinity meteoric waters causing in element and mineralogical zonations. Therefore, according to the studies of lithology, alteration, mineralogy, geo- chemistry and fluids inclusion, it can be concluded that mineralization at Chahshirin dis- trict has characteristics of an individual mineralization system. This system is related to evolution of hydrothermal fluid mineralization resulted in vein-veintle Cu mineralization.