Abstarct: Kooh Rig copper deposit is located in Semnan province, 150 km south of Shahroud and 18 km southeast of Toroud village. From a geological point of view, the studied area is located in the southeastern slope of the volcanic-sedimentary belt of Toroud-Chah Shirin and the southern part of the geological sheet of 1/250000 of Toroud. Volcanic and magmatic activities in this strip from middle Eocene to Oligomiocene have caused the formation of a set of submarine volcanic lavas along with pyroclastic rocks with similar composition and sedimentary interlaxyers. The most important rocks observed in the region include: basalt, andesite-basalt, andesite, trachyandesite, trachyte, tuff, agglomerate, sandstone, siltstone, shale and marl with middle Eocene age. The most important minerals of the deposit are: chalcopyrite, bornite, dignite, chalcocite, covelite, malachite, chrysocolla, hematite, goethite, limonite and manganese oxides along with quartz, calcite, barite, gypsum and clay minerals. The dominant structure of mineralization is vein and the studied textures include: vein-vein, fissure filling, open space filling, cavity filling and scattered grains. baxsed on the results of the study of the fluids involved, the dimensions of the fluid intermediates vary from 5 to 27 microns, and they are liquid and vapor in nature, and the homogenization temperature is from 125 to 208 degrees with an average of 177.5 degrees Celsius. The measured density varies from 0.926 to 1.014 grams per cubic centimeter, the average of which was determined to be 0.96. The degree of salinity was determined from 8.55 to 10.98 weight percent equivalent to table salt with an average of 9.72. The chemical nomenclature of rocks shows basalt, andesite basalt, andesite and trachy-andesite. In terms of tectonic location, they are related to the expansion (rift) centers and the subduction environment, and in terms of geochemical nature, they are in the calc-alkaline range. During the Upper Eocene-Oligomiocene time, igneous masses (with different chemical composition) penetrated into this complex, which are often observed in the form of sheet dykes with a general northeast-southwest trend in the Kooh-Rig region. The creation of hydrothermal cycle under the influence of intrusive masses has caused the washing of road rocks and the elements present in primary rocks have migrated to higher parts and settled along the faults and fractures. In addition to this process, the rocks of the route have been altered by chlorite, siliceous, cercite, argillite, carbonate, and iron oxides. Copper is the main component of the deposit, which shows positive correlation with iron and zinc elements and weak correlation with magnesium and silver elements. According to field, laboratory and geochemical studies, Kooh-Rig copper deposit corresponds to an epithermal copper vein deposit. In this research, first the characteristics of Kooh Rig copper deposit are stated and then the characteristics of Kooh Rig copper deposit are compared with a number of prominent deposits in Iran and the world, which are most similar to the Abgareh vein deposit in the sedimentary-volcanic band of Toroud- Chah Shirin, Kalchoye copper deposit in Urmia-Dakhtar belt and Nikoiye deposit in structural zone of Western Alborz-Azerbaijan. Also, this deposit has a significant similarity with Arzolar deposits in Türkiye and Yueyang in China.