Abstarct: One of the primary assessments of the origin of rocks in conventional and unconventional reservoirs is to investigate the potential and potential of hydrocarbonization and the type of product obtained from the maturity of organic matter. In this research, geochemical analysis of the Kazhdumi, Kangan, and Dalan formations in one of the central Persian Gulf fields has been used to analyze the Rock-Eval pyrolysis devices, gas chromatography and gas chromatography-mass spectrometry (63 Rock-Eval samples, 3 GC samples and 35 GC-MS samples). These studies include evaluating the maturity and Kerogen type and the genetic potential of the above-mentioned formulations. The Kerogen type is most commonly used type III that is susceptible to gas, while the Kazhdumi Formation has a small potential for oil production it shows the origin of continental organic matter. The samples are in the oil window to the gas and their genetic potential is in the medium range. Kazhdumi Formation, in spite of the known source rock of most fields inside Iran, does not produce commercial quantities of hydrocarbons in the studied field. In the Kangan Formation, the Kerogen type is mainly type II / III and less than type IV, and the genetic potential of this formation is moderate. The maturity of these samples in the oil production window (late-diagenesis-early catagenesis) has been due to the sedimentation of the redusing-semi-redusing environment and the effects of biodegradation on samples are not observed and the origin of organic matter in this formation is marines mater and with a few inputs from the lands mater. The samples of Dalan Formation is located in the oil and gas window in terms of thermal maturity, and the Krugin type is of type IV and less than type II / III, which is expected to produce gas from this formation. The origin of organic matter in the mentioned formation is continental. The genetic potential of the samples is moderate. Today, in developed countries, the shale gas systems in the group of unconventional reservoirs are in production. In order to evaluate the geochemical properties of unconventional reservoirs, a set of geochemical parameters was determined in the studied field and compared with the minimum threshold values in Barnett shale. According to the TR-RO diagram, the Dalan Formation is at the source of biogeneous gas and gas production. In the Kangan Formation, most of the samples originate from the production of biogenic gas and gas from origin rock. In the risk-plot diagrams of the Dalan and Kangan Formations, these formations are located in the oil window to the gas and considering the C20-above the Kangan Formation, for these reservoirs, it can be expected to be more mature and more capable of generating gas as an unconventional reservoir.