The research on the dendroflora of Chornobyl town 30 years after the accident at the Chornobyl nuclear power plant reveal that the taxonomic composition of the town green spaces comprises of 87 species and 8 decorative forms of 29 families, 26 orders, 2 divisions. The composition of plantations is dominated by trees (63%), bushes (30%) and winding plants (7%). Despite the natural succession processes over the past 30 years, the plantations of Chornobyl are dominated by introducers, which make up 57% of the total number of taxa. The study of test areas reveals successional changes in the abandoned phytocoenoses of the town, which led to the expansion of the alien invasive species Acer negundo L., Robinia pseudoacacia L., Fraxinus pennsylvanica L. and Parthenocissus quinquefolia (L.) Planch. The spread of alien invasive species is facilitated by droughts of long periods and the decrease in groundwater level. Climate change and the lack of proper agrotechnical care result in fungal diseases, damages caused by the semi-parasitic species Viscum album L. on decorative and fruit trees and bushes, both also leading to their expel from the town plantations.