The caves and open-air archaeological sites situated on the north slope of central Pyrénées have preserved some deposits which rise from the middle Pleistocene to the Holocene and contain remains from the cultural periods extending between the Acheulean and Metal Ages. Pollen analysis of fillings in the caves of Montmaurin (Montmaurin, la Niche, le Coupe-Gorge, les Abeilles, le Putois IV) and of several other sites in this area (Portel-Ouest, Mauran, Saint-Jean-de- Verges, Rhodes II, Portel-painted cave, Enlène, les Eglises, la Vache et le Mas d'Azil) supply palaeobotanical and palaeoclimatic informations directly correlated with the different periods of the human occupation. These results, compared wich each main peat-lacustrine sequences ...