Abstarct: Evaporates include a wide range of minerals, which can highly effect on reservoir quality. This study was carried out in the carbonate part of the Asmari Formation during three stages including: A) petrographic studies B) aqueous and hydrocarbon fluid inclusion studies C) petrophysical analysis of wireline logs for reservoir zonation of the Asmari Formation. baxsed on study of the core photographs and petrography of thin sections, eight sets of microfacies have been identified for the Asmari Formation. Facies association and their variations showed deposition of the Asmari Formation in a carbonate ramp system composed of the outer ramp, the middle ramp and the inner ramp. The anhydrite minerals in the Asmari Formation are existed in different forms of poikilotopic cement, pervasive pore filling cement, fracture filling cement, vein cement, nodular and laminated and bedded anhydrite. Microthermometry of the aqueous fluid inclusions within anhydrites of Asmari Formation showed that the average temperature during formation of anhydrites in the dolomudstone facies was 68.2 degrees Celsius, and the mineral-forming solution had an average salinity of 23.5 weight percent. Therefore, the anhydrite formation in this facies was simultaneous or before dolomite formation in the semi-closed to closed diagenetic conditions and low to medium burial depth. These situations were associated to the gypsum dehydration and gypsum to anhydrite formation or direct precipitation of anhydrite in the early diagenetic condition. In contrast, in the dolosparite samples, the average temperature during formation of anhydrite was determined to be 100.1 degrees Celsius and the average salinity of the solution was 16.4 weight percent. Therefore, the anhydrites in this facies are mostly related to a semi-closed to closed diagenetic condition, with relatively high salinity and semi-deep to deep burial depth. The fluid inclusions studies with ultraviolet light showed the presence of hydrocarbon fluid inclusions within anhydrites of the dolosparite facies of Asmari Formation, indicating that oil migration and reservoir filling occurred before anhydrite formation. The fluorescence color of hydrocarbon fluid inclusions were in range of yellow and blue, showing the possible two different sources of hydrocarbon. According to the petrophysical and wireline log analyses and also various lithologies, the Asmari Formation in the studied field was divided into four zones. The Zones 1 and 4 are identified as secondary reservoirs, zone 3 is the main reservoir, and zone 2 is a non-reservoir zone. The zone 3, which is composed of dolosparite facies, different factors including dolomitization, limestone dissolution and formation of anhydrite cement after reservoir filling caused the high reservoir quality. The zone 4 is similar to zone 3, but with the lower thickness of dolomitic laxyers. The zone 1 is composed of dolomudstone facies and fine-crystal dolomites. However, due to existence of primary dolomites which formed during the formation deposition, this zone accompanied numerous tectonic fractures, leading to improved reservoir quality.