Abstract: The oil olive sample was extracted with C2H5OH-H2O (80+20 by vol.) in a Soxhlet′s extractor at 90 ℃ for 24 h.An aliquot of the extract was used for separation on Kromasail C18 column,and a mixture of methanol and acetic acid solution (1+99) mixed in the ratio of 88 to 12 by volume was used as mobile phase flowing through the column at a rate of 1.0 mL·min-1.UV-detection at the wavelength of 215 nm was used in the determination.Reference material of maslinic acid was prepared from leaves of Eriobotrya japonica by the HPLC preparation system,giving purity of the product attained to 98.91%,which was used as the exteranal standard.Recovery and precision of the method were tested by addition of standard maslinic acid (20.0 mg) separately to 5 samples of oil olive and analyzed by the method given,value of average recovery found was 98%,and value of RSD (n=5) found was 1.21%.