Since the 1980’s, American mainstream environmental group have showed a prominent tendency of institutionalization. This tendency has resulted from steady growth of these group in strength and their conformity to the conservative orientation in American society since the 1970’s. American mainstream environmental group became institutionalized mainly through strengthening their own construction, introducing a prolonged cooperative mechanism among themselves and adjusting their forms of environmental struggle by advocating the socalled “Third Way” as the basis of cooperation. As a result, the mainstream environmental movement in the 1980’s and the 1990’s exercised extensive and profound impact on environmental group consciousness of American people, production and consumption of American society and even American environmental policies. However, as a result of institutionalzation, the structural and intellectual shortcomings of the MEGs were strengthened, and the breakthrough of environmentalism seems hard to achieve.

mainstream environmental group; institutionalization; “the Third Way”; United States group