The current trade negotiations' round has been called the development round in order to emphasize ambitious objectives in terms of poverty alleviation: halving the number of poor by 2015. However estimates from world economic models show little improvement for the Less Developed Countries. Moreover several models assumptions may overestimate gains and underestimate losses, especially in the poorest countries where numerous markets imperfections hold. It seems then necessary to avoid that poverty reduction be restricted to emerging countries that development policies and their funding in LDC be discussed simultaneously to trade negotiations.