Lately, the problem of biodiversity conservation is becoming more and more acute due to increase of anthropogenic impact. With the evolution of anthropogenic ecosystems, it also increases the vulnerability of species and biodiversity in general, as a result affecting ecological balance and environmental quality. The purpose of the researches was to evaluate the flora and fauna diversity in the Orhei urban ecosystem. The study was conducted during 2017 in 10 urban stations. Floral researches enumerate the presence of 146 species of magnoliophyte plants, grouped in 127 genera from 45 families. The most numerous were the species of the families: Asteraceae, Fabaceae, Rosaceae and Poaceae. The most frequents species are the eurybionte with wide ecological amplitude, some of which are included in the invasive species category. Vertebrates researches have revealed the fact, that the mammal fauna includes 29 species with a higher effective in the green areas of the urban ecosystem. The birds population of the ecosystem enumerate 58 species, prevail those from order Passeriformes.