Abstract: The contents of polyphenol, flavonoids, polysaccharide in the bulb of Oxalis corniculata L. were measured by ferrous tartrate method, erinitrit-aluminum nitrate-sodium hydroxide method, phenol-sulfuric acid method and DNS method. Using acetonitrile and 0.1% phosphoric acid as mobile phase and gradient elution, the fingerprints of different polar parts of alcohol extract of Oxalis ferruginosa were investigated. The antioxidant activity in vitro was determined by 1,1-diphenyl-2-picrylhydrazine radical scavenging method and hydroxyl. OH radical scavenging method with ascorbic acid as positive control. The polyphenol contents of the two parts were 5.45 and 4.73 mg/g. The flavonoids contents of the two parts were 16.62 and 7.70 mg/g. The polysaccharide contents of the two parts were 17.00 and 121.02 mg/g. 32 peaks were calibrated on the basis of peak 21, and 31 inner cores were calibrated were set at 280 nm. The common peaks in different polar parts are the outer skin： petroleum ether phase 8, chloroform phase 22, ethyl acetate phase 22, n-butanol phase 26, water phase 9; inner core： petroleum ether phase 14, chloroform phase 21, ethyl acetate phase 17, n-butanol phase 19, water phase 10. In the determination system of antioxidant activity, the outer skin and inner core of bulb had certain antioxidant activity in different polar parts. The chloroform phase and ethyl acetate showed better antioxidant activity than the two free radicals. The contents of polyphenol, flavonoids and polysaccharide were rich in the bulb of Oxalis corniculata L.. After extraction by petroleum ether, chloroform, ethyl acetate and n-butanol, the chemical fingerprints and antioxidant ability of the ethanol extracts were different, which could provide reference for the discovery of effective substances in the later period.

Key words: Oxalis corniculata L., active ingredient, poite, fingerprint, antioxidant activity