This paper conducted an indepth assessment on the efficiency of the impacts of trade agreements on rice exports during the period from 2000 to 2015. Based on the secondary data published by the General Statistics Office of Vietnam and the World Bank, the study employed random boundary gravity model to quantify the capacity of Vietnam to exploit rice export potential when participating in trade agreements, or in other words, to estimate the inefficiency in operation of rice export activities of Vietnam under the impact of trade agreements. The results show that rice export activities have not promoted well (at a low level) the impact of the trade agreements that Vietnam has participated in and not all trade agreements have a trend to increase the capacity to exploit rice export potential. Since then, this study provides some recommendations to improve the impact of trade agreements on rice exports in developing countries including Vietnam.