Abstract: The Platycladus orientalis was developed in the dry and warm climate of forest-steppe during geological times, 2--3℃ warmer than the climate of such regions at present. This region is center of abundance of this species of plant. Owing to the limitation of biological factor, no zonal predominance of the plant was formed. As the supply of water and heat in these regions decrease gradually from the south to the north, corresponding changes of the Platycladus orientalis forests occur in the composition of species, stratification and structure of synusia as well as the ecological types of the plant. The present center of abundance of the Platycladus orientalis will not shift if no great fluctuations occur in the supply of water and heat in the future.