Lao PDR is a country with a potential for new hydropower plants, with total installed capacity of 28,000 MW.Xayaburi Hydropower Dam Project has been completed and it has a capacity of 1,285 MW.Xayaburi Hydropower Project is involved by numbers of stakeholders with various interests.Effectiye management and environment considerations are important to ensure sustainable development within the hydropower sector.Even though substantial improvements in policy procedures, legal requirements and assessment guidelines have been made, there is still room for improvements.It is imperative, according to the Government of Lao PDR, especially taken the recent negative comments and criticisms in online news and reports about the dam into consideration.During the research for this thesis, the author has interviewed and collected information from personnel in many departments of the Government of Lao PDR, including the National Assembly, Ministry of Natural Resource and Environment, Ministry of Energy and　　Mining, Ministry of Planning and Investment, Resettlement Management Unit.Many of the interviewees were in charge of works related to Xayaburi Dam, and they helped prove many aspects about the project that international community has not yet recognized.A major problem is related to the preservation of the environmental along Mekong River regarding navigation lock, fishes passing facilities and flowing of sediment which are the most concern of Non-NGOs of Vietnam and Cambodia.Whether the project has been constructed in compliance with the main contract such as Mekong River Agreement 1995 and performance of Procedures for Notification, Prior Consultation and Agreement (PNPCA) and other laws related to the construction of the dam shall be examined.As evidences shown, the construction of Xayaburi Hydropower Dam is sustainable, transparent, and with minimal adverse social and environmental impacts, including but not limited to the amended dam structure and increased construction budget.The aforementioned dam is positive to economic development.Xayaburi Hydropower Dam has been constructed in accordance with the requirement of Lao citizens.Meanwhile, it will promote the development of the energy market for development and help lift Laos from the list of least developed countries.A balanced result can be reached in economic integration, social development and environmental protection.As the Mekong River Commission, the Government of Lao PDR and the Projects owner stated, Xayaburi Hydropower Dam will become the best model for other dams planed to be constructed along Mekong River in ensuring an environmentally sound development.