Abstract: Shale gas is different from conventional gas that most developed, it shows uniqueness in generation and accumulations, and the method to discriminate shale gas also differs from those for conventional natural gas. Total organic content and maturity level are key parameters used for shale gas evaluation. By the knowledge of these geochemical parameters, in addition to the loss of available samples for geochemical analysis, well logging data could be used for calculating these two parameters and be a great benefit to shale gas recognition. Total organic content represents the potential of shale gas generation and maturity level represents kerogen's thermal maturity, both are combined to indicate the amount of gas stored in shale reservoirs