When the war ended and the era of construction started, limiting the government to sovereignty activities and reducing its role in commercial activities, was on the agenda of the country's planners. So the separation of sovereignty and commercial activities of government was pursued more seriously. This separation was extended to all sections, including petroleum industry. By passing the Acts on Implementation of Policies under Principle 44 of Constitution and the Duties and Powers Ministry of Petroleum, it was attempted to implement the aforementioned separation in petroleum industry. This research by investigating different laws and regulations, evaluated the separation between sovereignty and commercial activities and the relationship between the sovereignty and commercial bodies in this sector. We conclude that, firstly, the relationship between sovereignty and commercial activities is longitudinal, so even if the government is prevented from taking action in a section, it continues to play its role in sovereignty activities. Secondly, the Law on the Implementation of Policies of Principle 44 added the criterion of "investment, ownership, and management" to the criterion of “ separation of sovereignty from commercial activities". Thirdly, despite the separation of the sovereignty from commercial activities in petroleum sector, the duties between them are not completely divided.