The Mongun-Taiga mountain massif is situated on the north-west of Inner Asia of contact between arid territories of Mongolia and semiarid and humid mountains of Siberia. The classification and structure of the highland vegetative cover is a question of detailed consideration. The dominant, indicative and characteristic species of the basic communities are characterized. For the reconstruction of climate and landscape changes in the past it is necessary to take into account not only the structure of altitudinal landscape zonality, but also deviations from it (aspect related and barrier effects).