Abstract: According to fiscal framework of the international petroleum contract, the total revenue of oil and gas fields is divided into two parts, which are the income of foreign contractors and resource countries.Therefore, the revenue share of resource countries can reflect the preferential degree of fiscal terms of petroleum contract.At present, the quick and direct method is widely used to calculate the share of resource countries, but it is not applicable to the comparison of all petroleum contracts, only is applicable to the comparison of product sharing contracts.Therefore, based on the comprehensive analysis of the investment environment by IHS, a well-known energy company, this paper puts forward the comprehensive index model method to calculate the indexes under the net cash flow model, comprehensively consider the share of resource countries and foreign investors, and make a comparison of fiscal terms of petroleum contract.This method can be applicable to the comparison and optimization between different countries and different petroleum contracts, and can reflect the advantages and disadvantages of petroleum contracts more objectively and truly than the quick and direct method.