This research is based on a two-month field work in the Comunidad Nativa de Shipetiari, a community of the Machiguenga ethnolinguistic group of the Peruvian South Western Amazon. Based on a socio-anthropological approach, the analysis considers the importance of social institutions and the role of social actors in the process of reformulating social order and identity definition, this in a context of constant dynamic change. The social uses and innovations of the "shamanic institution" machiguenga are the central elements of this work. To account for the role of social actors in the innovation of this social institution, I focus my observations on the personal journey of the Chamane Mateo Italiano, a charismatic character born in the Urubamba region 48 years ago. International, national and local contexts are presented to better understand the framework within which this "Shamanic institution" is part. The influence of external actors (conservation and development NGOs and researchers, mainly) is now part of the history of the Comunidad Nativa de Shipetiari, created about 15 years ago in an important conservation area (between the Manu National Park and the Amarakaeri Communal Reserve). The presence of various conservation and development projects has left traces at the local level, particularly in the reinterpretation of speeches, but also in the practices related to the management of natural resources through "local ecological knowledge". In this research, I focused in particular on observing the recovery of knowledge related to phythotherapeutic practices and the use of medicinal plants. Interactions between cultures with perceptions of reality and different lifestyles create reflections on the concepts of "indigenous" and on the dichotomy between "traditional knowledge" and "Western knowledge". The concept of "hybrid and located knowledge" seems to be adapted to the knowledge gained by shaman and machiguenga cosmology. The personal journey of the Chamane Mateo Italiano led him to develop a community project, the Traditional Medicine Centre, which is now funded by two major international organizations (UNDP and GEF). This work thus highlights that openness and intercultural dialogue are cultural strategies in the game of identity and difference.