As observed in many developing countries the Peruvian government is willing to establish a system of science, technology and innovation, decentralized, plural, and oriented by demand through the private sector. From 2001 to 2010 the INCAGRO project financed by the World Bank designed a new way to identify and finance innovative experiences in rural areas by generating knowledge and technologies useful for stakeholders to improve their productive activities and then their livelihoods taking into account the environmental and social dimensions of the development. The article is aiming at analyzing the role of public action aimed at promoting innovation systems by mainly strengthening POs working in order to stimulate innovation processes and service provision to farmers within different value chain. The agricultural innovation system provides a relevant framework to analyze innovation processes. It highlights some elements to be taken into account to understand the innovation process : the resources and strategies of each stakeholder, the relationships between stakeholders, their social networks. The innovation system could be analyzed at national level focusing on relationships between research organizations, education organizations,extension, private firms. The innovation system could be analyzed at local level on relationships between actors involved in economic activities. In this sense the actors involved in a value chain and the actors providing assistance or services to these actors form an innovation system. Some authors argue that a few actors may play a specific role by strengthening the interactions, increasing the flow of information, or facilitating the negotiations between actors. PO could play such a role because it is an intermediary organization between farmers and the outside world. We carried out a study to better understand the contribution of the projects financed by INCAGRO to the innovation system at value chain level. The objectives of the stud