Abstarct: The study area (Dehmola) at a distance of 20 km southwest of Shahrud belongs to a part of the wide eastern Zoghal dar area. Formations of Precambrian (Soltanieh formation) to upper Jurassic (Dalichai) can be observed in the stratigraphic columns of Dehmola area, thus, Shemshak formation with dominant lithology of shale (green, black and charcoal), sandstone and coal laxyers, that is one of the biggest and the most important formations of the area, was selected as the goal of most organic geochemistry studies examining the hydrocarbonization potential of Shemshak formations shales in Dehmola area. Because many subjects associated with shale behaviors, particularly environmental and economic geology, inorganic geochemistry and also organic geochemistry, are controlled by lithological characteristics of the source rocks and related closely together, each subject will be addressed in an individual chapter. Mineralogical composition of all study formation shales that is baxsed on the results of XRD, XRF, ICP instrumental analysis and also the studys of SEM / EDS micrographs, points to the presence of quartz, feldspar, iron and micaceous minerals (muscovite, biotite and chlorite). Zircon, dolomite, sulfide minerals (pyrite), are among the trace elements recorded by X-ray diffraction of black and charcoal shales of the study area. The normalization of shales of the study area especially black and charcoal shales, to references including NASC, PAAS, shale global average, neogene shale of the Surma group from Bengal, Bangladesh points to the anomalies of rare soil elements especially Ce and La, trace elements U, Th, Mn, As, etc., and also demands the high importance of economic studies and specific environmental considerations. In most cases, green shales did not show any particular element anomalies, but in some cases (such as uranium and thorium) showed severe depletion. High amounts of quartz and illite in studied shales as well as the use of common ratios of trace elements such as La / Th, also referred to the derivation of the felsic sources with granodiorite composition, in addition to the dominancy of detrital controllers. According to the use of diagrams associated with the determination of the history of the source rock weathering or A-CN-K and A-CNK0FM and high concentrations of Al2O3 and also CIA> 50, Shemshak formation shales have endured severe weathering in the source area. Shemshak formation sandstones that in most areas showed the signs of varnishing and alteration, consist of quartz, feldspar, chlorite, mica, rubbles and also iron oxide, and are likely belong to arkosic sandstones. Coals of the zone also represent the dominant composition of vitrinite and inertinite Organic geochemical studies of shale samples results baxsed on the application of Rock-Eval pyrolysis 6 instrumental analysis are summarized as below: 1. The type of the majority of samples with a range of organic matter of TOC = 0/08-23/4 belonged to kerogen types III and IV that included mature to hypermature in terms of the spectral thermal maturity. While the darker samples show higher thermal maturity. 2. Most of the shale samples are located in gas zone, dry gas and entry to mextagenesis phase in terms of the production potential. 3. Distribution of HI values in relation to OI and also the use of TOC values suggest the D facies boundaries in the majority parts of the study area indicating continental and extremely oxidant environments. 4. Organic geochemical analysis performed (Rock-Eval pyrolysis) on samples suggests the presence of a significant amount of organic material rich in oxygen (relatively high OI), poor in hydrogen (low HI) with continental or marine origin.