Aganonerion polymorphum leaves are one of the popular vegetables in Binh Dinh province. By characteristic reactions, it was found that the leaves contain triterpenoid, alkaloids, steroids, cardiac glycosides, saponins, phenolic compounds and coumarins but no flavonoids. By chromatographic method, ursolic acid (G4) was isolated from ethyl acetate extract. The structure of this compound has been elucidated by modern spectroscopic method: MS, 1H-NMR, 13C-NMR, HSQC, HMBC and being compared to results published articles. Ursolic acid is a compound isolated for the first time from theAganonerion polymorphum leaves. In addition, ethyl acetate extract has the ability to inhibit the growth of Staphylococcus aureus at IC50 = 195.821.55 (µg/mL) and Lactobacillus fermentum at IC50 = 186.473.50 (µg/mL).