Studies on invasive species have become more numerous in the last two decades, which has led to the development of a new branch in the field of ecology - the ecology of invasion. Knowledge of non-native, invasive or potentially invasive species in various ecosystems, as well as their impact on local plant communities is a priority in biodiversity research. Invasive species are modifying natural ecosystems by the: degrading fertility, modification the physico-chemical properties of the soil, degrading the quantitative and qualitative characteristics of the vegetation mat that compete aggressively with native species for water, light, area. These invasive plant species are a major current problem and a major threat to the Earth's biodiversity. This paper aims to analyze the taxonomic structure, ecology and impact of invasive plant species on urban flora, economy and human health from the Balti urban ecosystem. Our research conducted in the Balti urban ecosystem over the last three years has shown that 18 non-native species, or 13% of their total number, are invasive species. Thus, we identified 18 species of invasive plants, which are part of 9 families, mainly species from the family Asteraceae, in number of 9, Brassicaceae with 2 species, and the other families with only one species. The study on the origin of invasive species showed that half of the numbers of species are North American, followed by the Eurasian, Mediterranean and South American center of origin. Invasive plant species of North American origin are the most common, which is explained by the fact that the climatic conditions of this continent are similar to those of the Republic of Moldova. Invasive species cause enormous economic damage to agriculture, forestry and human society. One of the invasive species that can cause allergic diseases or even intoxication of many people sensitive to their pollen is Ambrosia artemisiifolia L., which is a very aggressive species, native to North America, when it develops en masse it produces allergies, with effects of more diverse in those affected.