Plant macrofossil analysis was performed on a peat core collected from the Mozgovitsa valley in the Northwestern Pirin Mountain. The results were combined with the information from pollen analysis and radiocarbon chronology so that a detailed palaeovegetation reconstruction for the last 9500 years was presented. Betula forests with groups of various Pinus species had dominated the landscape 9500-7300 years ago, while mixed deciduous Quercus forests were distributed below them. From this period the first macrofossil record of Picea abies indicated its presence in the study area. The change to a more humid climate after ca. 7500 years ago had resulted in the formation of a coniferous belt composed of Pinus sylvestris, P. peuce and Abies. Around 3000 years ago P. abies had started to expand in the coniferous belt and shaped the tree-line with P. sylvestris and P. peuce. The fossil record indicated an intensification of the anthropogenic impact on the natural egetation since historical time by practicing animal husbandry and deforestation to obtain pasture land.