Abstarct: Heydar Abad antimony deposit is located in Sistan and Baluchestan province and 222 km Northwest of Zahedan city. The study area is located in the North part of Iranian flysch zone Eastern. Stratigraphic sequences in the study area related to the third geological period and include the following rock units: Ultrabazic upper-Cretaceous, Eocene flysch, conglomerate and Oligomiocene sandstones, Tuff sandstones - Oligomiocene sandstones, Volkanic Oligomiocene and Dyke are Sill The Oligomiccene conglomerate rock unit is the main host of the antimony mineralization at Heydar Abad. The alterations of the ore are as follows: sillicic, argillic, carbonate and iron oxide - hydroxide zones. baxsed on microscopic studies, and results XRD and EPMA analysis the antimony minerals of this ore deposit include stibnite (antimony sulfide), senarmontite (antimony oxide) and stibconite (antimony hydroxide), Pyrite sulfide mineral is associated with minor amounts in the study area. The gangue minerals in the study deposit include quartz, calcite, dolomite, hematite, goethite, limonite. baxsed on field evidence, manual specimens and microscopic studies, the main texture of mineralization, including vein – veinlet and its major textures include open space filling, vein - veinlet, massive, blade and replacement. According to the results of ICP-MS analysis of samples (129 samples) taken from the surface and depth boreholes in the study area, antimony element level is reduced from the surface (170000 ppm) to a depth of 32000 ppm. Antimony showed the highest correlation coefficient with the lead element. Also, baxsed on the results of the microthemobarometric analysis, the primary fluids are more likely to be bi-phasic L + V with varying sizes and an average of about 5 microns. Microthemobarometric studies show fluid temperatures, temperature range 110 to 190 ° C, and salinity 4 to 14, which is equivalent to weight percentages of salt and pressure range less than 50 times. The depth of fluid trapping the middle depth of the deep fluid is less than 188.8 M above ground level. The fluid in Hyder Abad antimony deposit has low to medium salinity, indicating the mixing of atmospheric fluids with low to moderate salinity magmatic fluids.The effective factors in antimony mineralizatin in Heydar Abad deposit are: origin of antimony, origin of fluids, structural control and geochemistry factors. baxsed on results of this studies of Hyder Abad antimony is classificated in stibnite-quartz vein hydrothermal deposit type.