OBJECTIVE:To establish the quality standard of Smilacina japonica. METHODS: S. japonica was identified qualitatively in respects of original plant morphology,character,microscopic identification,TLC,etc. The moisture,ash and extract of medicinal materials were determined. The content of(25S)-17α-hydroxy-5α-spirostane-9-ene-3β-O-β-D-glucopyranoyl-(1→2)-[ β-D-xylanosyl(1→3)]-β-D-glucopyranoyl(1→4)-β-D-galactopyranoside(SJ-13) was determined by HPLC. The determination was performed on Waters SunFire C18column with mobile phase consisted of acetonitrile-water(35∶65,V/V)at the flow rate of 1.0 mL/min. The detection wavelength was set at 203 nm and the column temperature was 20 ℃. The sample size was 10 μ L. RESULTS:The original plant was perennial herbal,with height of 30-60 cm. The surface of the medicinal material was brown to brownish brown,with wrinkle and 1 row cells in epidermis. The powder of medicinal material was grayish yellow and contained large amount of acicular crystal. TLC spots were clear and well-separated. The content of moisture was 5.26%-8.88%;the content of total ash was 4.60%-28.86%;the acid-insoluble ash was 1.56%-23.39%,water extract was 23.84%-51.26% and alcohol extract was 22.65%-57.36%. The linear range of SJ-13 were 8.92-31.22 μg(r＝0.999 9). RSDs of precision,stability and reproducibility tests were all lower than 1%. The average recoveries were 97.0%-99.2%(RSD＝0.8%,n＝6). RSD of durability test was lower than 1%. The content of SJ-13 was 4.40-29.80 mg/g in 10 batches of medicinal samples. CONCLUSIONS:The content of water, total ash,acid insoluble components should not exceed 11%,35%,28%;the content of water extract,alcohol extract and SJ-13 should not be less than 19%,18% and 4.40 mg/g,respectively. Established standard can be used for the quality control of S. japonica.