An area along Mekong River in north-east Thailand was covered by dry Dipterocapa forest, which is one of the tropical in the part monsoon forests. And also lasted ecosystem related Mekong River and regional foundations. In the 1970', they started development of power sources and farmland, Irrigation using water resources of Mekong River. At the same time, aquatic ecosystem was changed for reasons of forest decreasing, damage from salt. After that, concerted neighborhood action to demand environment preservation has developed. In the 1990', Thai government declared policy of green planning of land "ISAN KHIAO", rising to 40% of forest cover. This paper reports the current situations of development and foundational environment along Mekong River in north-east Thailand.