The thesis seeks to explain the meaning and the process through which the new coalition of developing countries, the G-20, was formed, in the preparatory phase of the negotiations to be held at Cancun Ministerial Conference of WTO (2003). The work analyses the role of this developing country coalition throughout the negotiations of the Doha Development Agenda from the perspective of the revival of the North-South dialogue and its implications for the influence of new emerging markets over the multilateral trade arena. Concentrating our focus on the negotiating process of the new institution, We argue that path dependency processes help to explain the dilemmas faced by the G-20 in striving for keeping its cohesion around the defense of Doha Mandate, centered in its right of development. Despite the fact that developing countries found themselves at the center of the negotiating proccess and entitled to exhert a higher influence on the progress of the negotiations, its defense of the legitimacy of the Doha mandate was increasingly put to test before the fragility of its cohesion when the negotiating proccess turned to the substance of a concrete agreement.