Abstarct: Unconventional shale gas reservoirs, are producing gas in developed country now. A safe and long time sourse of energy could be provid by developing shale gas systems in Iran. Therefore investigation on Garau & Sargelu as unconventional reservoirs has come to attention of oil industry. In this study, the organic geochemical characteristics of these two formation, the located in Lorastan, has been investigated. For this purpose, a study of the properties of Barnett shale was done and a set of gochemical parameters were defined and their values-in Garau and Sargelu compared with minimum threshold values in Barnett shale. Samples in both formations have a combination of kerogen of type III and II / III and IV. The samples are location maturity levels of the late oil window to dry gas window. These samples were formed in different conditions of sedimentation due to changes in environmental conditions before and retreat of sea water. According to the thermal maturity for Garau Formation in boreholes the maturity towards West have shown a increasing from oil window to gas window. The in Sargelu formation, from the south to the center the maturity have in creased occur. baxsed on calculations of total hydrocarbons for Garau and Sargelu, it is equal to 154.10 and 35.46 (bcf / section) (amount of oil and gas production for the Garau 114.04 and 40.07 (bcf / section) and to the Sargelu 5.73 and 29.73 (bcf / section)), The total gas preserved in the formation of the Garau and Sargelu is respectively 37.47 and 12.97 (bcf / section). The values is not very good in compare with Barnett Shale. X-ray diffraction and mineralogical study was showen that Garau formation of clay mineral content of less than 4% (3-4%), quartz (25%) and carbon (70%) and for drill targets will be suitable. Evaluation studies show that Garau formation in the Lorestan province can be considered as shale gas.