Abstract: NAFTA is the first trade agreement to reconcile trade and environmental interests between developed and developing countries. This article adopts a “pressure-status-response” framework to analyze the environment effects of NAFTA from the following four aspects, including enterprises, production technology, infrastructure, social organization and government policy. The conclusion is that environment effects of NAFTA depend upon the response of social organization, the implementation of government policy, enterprise's operation and related infrastructure. Positive environment effects have been observed in above three aspects, except that in infrastructure. And only if social organization and government policy operate normally, NAFTA will finally produce positive environment effects.