The primary objective of this study is to investigate into using natural gas in Vietnam in the most efficient and sustainable way. Besides, the research also aims to understand the pathway for economic growth of corporate and study about energy security and environment safety. Three findings of the research as follow: Firstly, if Petro Vietnam Gas Joint Stock Corporation (PV Gas, GAS, corporation) has corporate strategy in terms of free market, it would add more values to the key stakeholders including the government, community, Petro Vietnam Group (PVN, group), Corporation, their customers, subsidiaries, distributors, suppliers and staffs. Secondly, PV Gas is concentrating on energy security more than economic growth, which has lowered its financial results. Thirdly, as natural gas is a limited resource, PV Gas should research more on substituted energy as well as treatment of high CO2 content gas reserves. Therefore, the principal conclusion is that energy industry is not Monopolistic Competition but Oligopolistic; the only way is to apply Game theory on their strategy to achieve the best.