Kalchoyeh copper deposit is located about 110 km east of Isfahan, in Central Iran, Urumieh- Bazman volcanoplutonic belt. Host rocks of this deposit are Eocene volcanic rocks and tuffs which are pyroxene andesitic lava and sandy and lithic tuffs. Sandy tuffs are the main host rocks of the deposit. Ore mineralization is taken place as veins and veinlets and quartz is the main gangue mineral. Hypogene mineralization includes chalchopyrite, galena and magnetite. Covellite and chalcocite are also found as supergene mineralization. Microthermometric measurements of fluid inclusions in quartz indicate homogenization temperatures between 101 to 312 °C and salinities from 0.7 to 7.3 wt % NaCl equivalent. Boiling occurred in the mineralizing fluids at 400 meter below the paleo- water table. Based on performed studies, ^Ore fluid was low to medium temperature and low salinity and potential mineralization. In addition ore mineralization in Kalchoye is type of epithermal deposits with low sulfidation.