The aim of this paper is to present the possibilities of development of trade, production, demand, and prices in agri-food sector of the ASEAN countries in view of changes caused by implementation of the new agricultural agreement negotiated under the WTO auspices. A general equilibrium model Global Trade Analysis Project was used in the research to make ex ante projections. Based on the GTAP simulation it can be concluded that having cost-price advantage and taking advantage of freer access to the markets of the highly developed countries, the ASEAN nations may increase the volume of agricultural production and export. In consequence, they may benefit from the liberalization.