in order to improve and update iranian upstream contracts in oil and gas industry, the ministry of petroleum propose a submission to renew the old version of oil contracts that are so-called buy-back. After 4 years that the bill enacted, council of ministers enacted the new model for upstream contracts and revised it number if times with this title: "Iranian Petroleum Contracts" breifly cited as "IPC". This article focuses on these revisions that reveal the nature and purpose if new ,odel contracts in oil and gas industry. It concluded the production sharing (PSA) agreements has not been banned, despite of historical and political belief. this conclusion is in full comliance with upstream laws and regulations and does not have any conflict with constitutional rules of Islamic Repiblic of Iran. Ther are some diversion in legal approach toward upstream contracts in oil and gas industry that illustrated detailed in this research.