This thesis examined livelihood strategies of villagers on both sides of the Mekong River, especially those of Pak Ing villagers in Chiang Khong district, Chiang Rai province. The economic cooperation development projects in the Mekong Sub-region had exploited economic benefits from the river and drastically changed the lifestyles of people living on both sides of the river. They included a construction of mega-dams in China and blasting of rapids for commercial shipping. Villagers encountered the crisis of dwindling fish numbers and had to find out new strategies for their threatened livelihoods amidst changes. They established and maintained good relationships among themselves and developed relationships with non-governmental organizations in an attempt to solve their problems, to provide benefits to one another and to demand their rights.