Abstarct: Parsian Copper deposit located in Semnan Province, 140 Km Southwest of shahrood and part of a Torud - Chah shirin volcanic- sedimentary belt that has facies in the northern edge Structural- sedimentary zones of Central Iran.Field and petrographical studies, deposit area, consist of Pyroclastic Rocks (Crystal Tuff, Lithic Tuff, breccia Tuff, Agglomerate Tuff) and contains less includes Basaltic trachy andesite Lava that indicate middle- upper Eocene and Conglomerate. The rock are high-K, calc- alkaline in nature and are formed a magmatic arc setting in a subduction zone. Mineralization in Parsian area occurred as veins along the fault planes in a Pyroclastic and Lava units. Fractures resulting from operation of faults in the rocks of the region have created a favorable location for the influence of solution and it is considered as the main controller of mineralization. According to the field observation and mineralogical studies, the mineralization in the region was carried out in two stages: hypogen (pyrite, chalcopyrite and chalcocite) and supergene (malachite, covellite and chrysocolla). The most important Alterations including: argillic, sericitic, carbonatic, chloritic, silisic and iron oxide. the most textures observed in the occurrence of mineralization include vein-veinlets, open space filling, replacement, Radial and disseminated.In chondrite and primitive mantle normalizing diagrams they have significant enrichment in LREE (k and pb) and HFSE (Nb and Ti) witch related to the subduction zone and crust company is in magmatic processes. Geochemical studies indicate that copper has only relative correlation with silver. Since silver has not founded as an independed crystalline phase. Fluid inclusion data shows in the temperature range from 85 to 146 ˚C and salinity between 0.88 and 8.68 Wt% NaCl and minimum depth of 150 m. Most of thee studied fluid inclusions are from liquid rich two phases (L +V) type. On the baxse of a formentioned evidences, the principle deposition mechanism of ore minerals was mixing of two meteoric and magmatic fluids. Finally, regarding our research the petrography, struactural control of mineralization, alteration type and its extention, simple mineralogy, geochemical, fluid inclusion properties of the study area and comparion with similar epithermal deposits indicate that the Parsian vein system is formed in a low-sulfidation epithermal environment.