We propose in this article a methodological reflexion about the qualitative and quantitative representativeness of charcoals in the grounds from pastorales and agricultural practices of fire in the Pyrenees. We present a method of study of charcoals from current and recent fires in order to establish a reference frame allowing to clarify the reading of the anthracological diagrams. We do not have any result here because the analyses are in hand, but the aim is to show the importance of the knowledge of the practices of fires for better including/understanding the representation of their carbonaceous vestiges. It is essential to start from what one can check today in order to interpret the data palaeo-environmental. Each site of study, the forest of Antenac (Luchon) and the Pays de Sault were selected according to the frequencies of fires known for the first, and of historical works providing of detailed maps on the forest formations, the moors and the clearings since the Reformation of 1669 until the current one, for the second. Each site was treated according to a specific experimental protocol presented in this article.