Rhizoma Smilacis Glabrae, also called tufuling, is one of the commonly used herb in traditional Chinese medicine for detoxication, relieving dampness and diuretic. It is also one of the main ingredient in Guiling gao; an old traditional functional food in Southern China and Hong Kong. The modern pharmacological studies reveal that the methanol or water extract of this herb is anti-inflammatory, immunomodulatory, protective against hepatocyte damage, and insulin sensitivity enhancement [1,2]. To further explore the biological effects and potential application of this herb, quality control of it is very important. A cyclodextrin-modified capillary zone electrophoresis (CD-CZE) method was established for the separation and determination of trans-resveratrol, astilbin, taxifolin, shikimic acid, syringic acid and ferulic acid; the main organic acids in Rhizoma Smilacis Glabrae. With running buffer of 20 mM borax with 2 mM β-cyclodextrin at pH 9.46, the six compounds were successfully separated within 8 min with the applied voltage of 25 kV, temperature of 25oC and detected at UV 214 nm. The effect of β-cyclodextrin was investigated in detail. The results showed that β-cyclodextrin can increase the electrophoretic mobility of some analytes through complexation and improve the separation performance. The formation constants of trans-resveratrol, astilbin, taxifolin and ferulic acid with β-cyclodextrin were calculated and the values were 1580±35, 1578±37, 516±21 and 81±8 L mol-1, respectively. P-coumaric acid was used as an internal standard to improve the CE performance. The RSD of migration time ranged from 0.07 to 0.30% while those of the peak area ratios (analytes perk area/ internal standard perk area) ranged from 2.66 to 4.12% for six determinations of analytes at the concentration of 5 and 25 μg mL-1. The correlation coefficients of the calibration curves of analytes were all >0.999, and the recoveries were from 97.5 to 108.3%. The method was successfully applied to determine these bioactive components in the 12 samples of Rhizoma Smilacis Glabrae from different locations in china. The results found that the content of astilbin ranged from 11.5 to 47.6 mg g-1, which was the most dominant active compound in Rhizoma Smilacis Glabrae, while ferulic acid, syringic acid and resveratrol may not be present.References1. J.Y. Jiang, Q. Xu: Immunomodulatory activity of the aqueous extract from rhizome of Smilax glabra in the later phase of adjuvant-induced arthritis in rats. J Ethnopharmacol 2003,85: 53-59.2. T. Chen, J.X. Li, J.S. Cao, Q. Xu, K. Komatsu, T. Namba: A new flavanone isolated from rhizoma Smilacis glabrae and the structural requirements of its derivatives for preventing immunological hepatocyte damage. Planta Med 1999, 65: 56-59.