Based on the analysis of field materials collected during our field trips in 2017-2021, literature data and specimens stored at the Herbarium Fund of the Institute of Botany, a list of alien representatives from the families Amaranthaceae Juss., Asteraceae Dumort. and Poaceae Juss. found on the territory of Azerbaijan has been compiled. It was established that the family Poaceae, represented by 10 genera and 15 species (21.74%) of the total alien flora of Azerbaijan), Asteraceae - 8 genera, 13 species (18.5%), Amaranthaceae - 2 genera, 8 species (11.4%). Most of the plants are herbaceous annuals with seed propagation. Most of the species, especially xenophytes were brought to the territory of Azerbaijan unintentionally. In ecological terms, according to the moisture factor, most could be distinguished in the following ecological groups: 21 species to the mesophytic, 13 species to the xeromesophytes and 4 species to the hygromesophytes. Some species – Amaranthus retroflexus, A. albus, Ambrosia artemisiifolia, Erigeron canadensis, E. annuus, E. bonariensis, Xanthium strumarium, X. spinosum, Digitaria violascens, D. horizontalis, Paspalum dilatatum should be considered the most dangerous, occupying natural and semi natural communities or migrating and naturalizing in disturbed habitats. The species listed above are introduced into forest, meadow, and shrub communities and at present, they are components of the herbaceous layer in these communities. Siegesbeckia orientalis, Tanacetum vulgare, Bromus carinatus, B. catharticus, Chloris virgata, Pennisetum alopecuroides, previously mentioned in the literary sources of Azerbaijan, were not found by us. The biological features of the identified plants (short life cycle, high endurance, seed propagation, the ability to adapt to new or stressful environmental conditions) ensure their successful introduction into local ecosystems. Based on the frequency of occurrence and abundance of alien plants in introduction places, the invasive role was considered and the status of invasiveness was determined. Most alien plants are characterized by the method of introduction as xenophytes and ephemerophytes by their role in phytocoenose.