A cyclodextrin-modified micellar electrokinetic chromatographic (CD-MEKC) method was established to determine five hydroxyanthraquinoids in Rhubarb. The five components were successfully separated by using the mixed micellar system consisting of 20 mmol/l sodium dodecyl sulfate (SDS) and 20 mmol/l sodium cholate (SC) with 10 mmol/l beta-cyclodextrin in phosphate buffer (pH 10.4). The separation was optimized by adjusting buffer pH, concentrations of beta-cyclodextrin and SC and applied voltage. The proposed method was validated and applied to the determination of two commercial Rhubarb samples. The results obtained were satisfactory.