Abstarct: Hajib mineral deposit is located in Qazvin province and 23 km southeast of Bueinzahra city. This area is a part of the central Iran, in particular is situated in the northern part of the Orumieh-Dokhtar magmatic belt. Eocene volcanic-sedimentary sequences cropped out in this area, and including pyroclastic rocks with andesite tuff and lithic tuff in composition, andesite and basaltic andesite lava, tuffaceous sandstone and sandstone. Andesite tuff and tuffaceous sandstone hosting ore-bearing silicic veins. Copper and associated elements mineralization in Hajib area is mainly mextal-bearing silica veins and In general, 9 silicic, silicic-sulfide and silicic-iron oxides veins have been observed in this area, that the number of 4 veins are important in length, width and grade in comparison with other veins .The alterations include propylitic (chloritization and epidotization), argillic, sericite, silicic, and iron oxides-hydroxides. The ore-forming minerals include sulfides (chalcopyrite, galena, bornite, chalcocite, covellite and pyrite), carbonates (malachite and azurite), iron-manganese oxides (hematite, oligiste, goethite, limonite and pyrolusite) and gangue minerals (calcite, quartz and barite). The main textures of mineralization are vein-veinlets and colloform, also structures include banded, vein-veinlets and brecciation. Geochemical studies show that parent magma of igneous rocks have calc-alkaline, mextaalumin and peralumin in composition, and also related to continental magmatic arcs. The multielements spider diagrams display that negative anomaly of Nb and Ti, which is main characteristics of continental arc- related calcalkaline magma. The contents of Cu, Pb, Zn, Au, and Ag are measured about economic grade occurrence in the Hajib silicic veins. baxsed on fluid inclusion studies, the homogenization temperature vary from 147°C to 250°C (average 234°C) and the salinity range from 0.87 to 13.06 wt%NaCl (average 6.07 wt%NaCl). baxsed on homogenization temperature and salinity, mineralization occurred at a pressure 10-100 bars and a density of 1 to 1.1 gr/cm3. According to the geological, mineralogical, alteration, geochemical, and fluids inclusion features, the Hajib mineralization introduce a polymextallic vein-type deposit.