This chapter presents the theoretical references and the methodology of Transbrasil research project (Dissemination of Brazilian public policies for family farming in Latin America and the Caribbean). Between 2015 and 2017, Transbrasil project has studied the different modalities of regional and south-south diffusion in Latin America and the Caribbean of two Brazilian policy models: Rural Territory Development and public food purchase from family farming. The main hypothesis of the research is that the South-South diffusion process reveals an "hybridization" of several forms of policy internationalization and diffusion: i) the policy-transfers approach; ii) the transnational circulation of norms and standards through international organizations mediations; iii) the regionalization and regional integration, especially through civil society and social movements. Considering this hypothesis, the research focused in two processes: 1) the characterization of the policy models in Brazil and of the transferred policies in the recipient countries; 2) identification and profile characterization of the main vectors, intermediaries or brokers of the policy diffusion(Brazilian and recipient countries` policy makers, international organizations, social movements etc.);. The method has associated literature review, documentary research and interviews with policy makers, beneficiaries and mediators in Brazil and in the recipient countries. In total, 68 interviews were realized. The diffusion of the public food purchase model was studied in Colombia, Haiti and Paraguay; and the diffusion of di Rural territory development in Argentina, El Salvador and Uruguay.