Abstract: Environment protection and sustainable development are the main trend at present. Forestry industry plays a special role in environment protection and sustainable development because of its particularity. Forest certification is considered an important method to promote the sustainable development of forestry industry, and becomes a new trade barrier in the international trade. Forest certification will certainly increase the cost of enterprise. This paper analyzes the substituting effect of forest certification against tariff barriers using a spaceprice gradient model, and gives suggestions.