The longest river in Southeast Asia, Mekong has been facing threat from the construction of dams. The naturally beautiful watercourse which originates from Tibetan hill ranges flows through six countries. The landscape delta in Vietnam is the boon of this greatest river. This river is a bio-diverse habitat and home for numerous dolphins which attract visitors from various countries. This river is considered as the largest inland fisheries in the world. Ecologists fear that the construction of dams may inversely affect the existence of biodiversities and freshwater fishes in the river. This situation will be a threat to the economy of Cambodia as well as Vietnam.