OBJECTIVE: To prepare high-purity rotundic acid, and to determine the contents of syringoside, peduncloside and rotundic acid in Ilicis rotundae and its refined products. METHODS: I. rotundae saponins was prepared by ethanol extraction method and hydrolyzed with methanol and sodium hydroxide; rotundic acid monomer was obtained after recrystallization. The contents of syringoside, peduncloside and rotundic acid in I. rotundae, its refined product 1 and its refined product 2 were determined by RP-HPLC. The determination was performed on an Agilent XDB C18 column with mobile phase consisted of water-acetonitrile (gradient elution) at the flow rate of 1.2 mL/min. The column temperature was 30 ℃, and the detection wavelength was set at 210 nm. The sample size was 10 μL. RESULTS: The purity of rotundic acid exceeded 99%. The linear ranges of syringing, peduncloside and rotundic acid were 0.18-3.22, 0.59-10.36 and 0.20-3.53 μg, respectively (r=0.999 9). RSDs of precision, stability (24 h) and reproducibility tests were all lower than 2.0% (n=6-7). The average recoveries were 96.08%-100.81%(RSD≤1.98%,n=6). The contents of syringoside, peduncloside and rotundic acid in I. rotundae were 1.61%, 7.26%, 1.29% (RSD≤1.08%, n=3); those of refined product 1 were 0, 82.59%, 4.18% (RSD≤1.67%, n=3); those of refined product 2 were 0, 73.29%, 7.41% (RSD≤1.15%,n=3), respectively. CONCLUSIONS: Prepared rotundic acid has high purity and is simple in preparation, safe and environmentally-friendly. RP-HPLC method that established is simple and reliable, and can meet the requirements for rapid analysis of I. rotundae and its refined products.