While natural and ecological integration in the Mekong River basin were well-sustained for thousands of years, for now being segmented by 6 national borders, the cost and benefit of the Mekong River development was divided with asymmetry structure. There have been serious controversies and conflicts among Mekong River riparian states with regard to various kind of the Mekong development, especially on the construction of hydropower dam in the Mekong mainstream. Recently the issues were even more complicated by the participation of private enterprises and Non-government organization(NGO). The article makes effort to synthesize the benefits and costs of each stakeholder who is participating in the Mekong hydropower development. Thus, this study attempts to make different research outcomes with the existing studies, observing the each and all perspectives of states, civil society, international organizations and enterprises on Mekong River development with objective descriptions. Then it analyses to recognize with balanced perspective what the essence and current affairs is on the Mekong River hydropower development. The article will also examines the distinct standpoints of each stakeholder groups, whether the support or oppositions on the Mekong River development, that were the states`` development strategy, economic interests, political power, environmental considerations and the rights to live of local residents in the River.