Abstarct: Zeydar iron ore deposit is located in 80km east of shahrood and about 25 km east of mayamey, on the Sabzevar subzone and northern end of central Iran structural zone. Lithological sequence in region with the general trend North east – South west, consists of Cretaceous limestone and units of clastic limestone, sandstone, marl, tuff, shale and conglomerate is the middle Eocene age. Iron mineralization has accurred as stratiform and concordant with beddly. Mineralization in primary, secondary and composed under the influence of weathering. The main minerals identified in the area include magnetite, hematite, pyrite, goethite, limonite and gangue minerals are calcite, chlorite, silica, gypsum and also in some cases clay minerals. baxsed on field observations, crafts and microscopic samples of tissue types, the main structures of the ore deposit consists of laxyered, lentiform and main textures are massive, disseminated, succession, coloform and skelletal. Chlorite altration as green in tuff unit is widest alteration in region. Other altrations are argillic, sericitic, silication, carbonatization and iron oxide alteration. baxsed on geochemical studies, binary ratios of Mn/Fe, Zn/V, Co/V, Cr/V and Co/Ni, located these deposite in volcanic-sedimentary deposits. According to V/Ti and V/Ni diagrams, deposit placed within the banded iron formation. Also according to the ratios of Al/Si and La/Ce, in seawater enriched by hydrothermal-exhalative fluids and is formed in sedimentary environment under Eh, pH changes. The pattern of trace elements normalized to crust enriched in Cu, Mn, Co, Ni and Zn and depleted in Ti, V, Sr that compared with bif types shows most similar to Algoma type. Chondrite normalized REE diagram indicating negative anomaly of Eu and a small amount of Ce, and HREE >LREE. In comparison with deposits types, Algoma-type most closely with this deposit. The Zeydar iron deposit from the view of tectonic and depositional environments, host rocks, geometry, mineralogy and structure display most similar to volcanic-sedimentary type iron deposits.