OBJECTIVE　To establish a CZE method for the simultaneous determination of magnolol and honokiol in cortex magnoliae officinalis and their supercritical fluid extract.METHOD　The buffer solution was 20 mmol*L-1 sodium borate(pH=10),the internal standard was sulfamethoxazole and the detection wavelength was 294 nm.RESULTS　Magnolol and honokiol in cortex magnoliae officinalis and their supercritical fluid extract were separated completely and determined accurately.The recoveries and the relative standard deviation were 99.40% and 1.6% for magnolol,and 98.44% and 1.4% for honokiol (n=3) respectively.CONCLUSION　The method was simple and accurate and it can be used for the quality control of magnolol and honokiol in cortex magnoliae officinalis and their supercritical fluid extract.