||Upper Volga basin is one of the industrial districts of European Russia with high level of urbanization. It includes Ivanovo, Kosrtoma, Yaroslavl, Vladimir and Tver’ administrative regions. The ecosystems of the area are strongly transformed anthropogenically. Present flora consists of 802 alien species, among them 116 species originate from North America. Less than half of North American species (46.6 %; 54 species) are successfully naturalized, 39 species invaded into the natural and semi-natural plant communities. 15 woody species (Acer negumdo, Amelanchier spicata, Fraxinus ptnnsylvanica, Physocarpus opulifolius, seldom Aronia mitschurinii, Padus pensylvanica, P. virginiana, Parthenocissus incerta, Symphoricarpos albus, etc.) invaded into different forest types and participated in the formation of underbrush. Juncus tenuis, Lupinus polyphyllus are common among herbaceous plants in disturbed forests. 13 species (Bidens frondosa, B. connata, Echinocystis lobata, Elodea canadensis, Epilobium adenocaulon, Solidago gigantea, Xanthium albinum, Zizania palustris, etc.) invaded into the bodies and riparian habitats, 11 species (Aster salignus, A. lanceolatus, Helianthus tuberosus, Hordeum jubatum, Lupinus polyphyllus, Oenothera rubricaulis, Palacroloma septentrionale, Solidago canadensis, etc.) – into the different types of meadows, 9 species (Lepidium densiflorum, Populus balsamifera s.l., Senecio viscosus, etc.) – into the open sand habitats and dry slopes, 6 species (Aronia mitschurinii, Epilobium adenocaulon, Linaria canadensis, Scirpus cyperinus, etc.) – into the moss bogs and peat pits. 27 species are aggressive, wide spread and play the role of transformers therefore they are included into Middle Russia Black Book. 7 species (Amaranthus albus, A. retroflexus, Erigeron canadensis, Lepidotheca suaveolens, etc.) mastered anthropogenic ecotopes. More than 60 species (Ambrosia artemisiifolia, A. trifida, Collomia linearis, Cuscuta campestris, Cyclachaena xanthiifolia, Lepidium virginicum, Panicum dichotomiflorum, Puccinellia nuttaliana, ect.) occur as casuals. Systematic control of North American invasive plant species and study of its biological characteristics should be continued in the Upper Volga region.