The Upstream Service Contracts in oil and gas industry of Iran have been used as an international contract for the exploration and development of Iran oil & gas fields, aiming to attract investment and establishing relationships with international oil companies (IOCs). These contracts explicitly or implicitly contain several statutory principles which are considered as a basic formation of the contracts. Such principles provide benefits for both national oil company (NOCs) and IOCs plus foreign Investors. Since those principles are considered to be mandatory rules prevailing on petroleum upstream contracts, thus, it would not be possible to derogate from such rules when negotiating and concluding these contracts. This parer is an attempt to investigate and find those principles and provided legal-economic analysis accordingly.