The aim of the research is a comparative study of the processes of formation of generative structures, flowering, pollination and seed formation in introduced species of the genus MeliaL. in the south of Uzbekistan. The highest coefficient of seed productivity is observed in 5-8-year-old trees - up to 17.1-18.6% in M.azedarachL. and up to 12.6-12.7% in M.toosendanSiebetZucc. With increasing age of plants, this indicator decreases. These are representatives of the genus MeliaL. has a high adaptive potential to the extra-arid conditions of southern Uzbekistan.