A reversed-phase high performance liquid chromatographic method was developed for the simultaneous determination of mannan and β-glucan in yeast cell wall samples using 3-phenyl-3-methyl-5-pyrazolone(PMP) as pre-column derivatization reagent.The polysaccharides in the sample were hydrolyzed with HCl into mannose and glucose form,and the contents of mannan and β-glucan were calculated with the concentration of each monosaccharide.The monosaccharides were derivated with PMP,and the derivatives were separated on a C18 column(4.6 mm×250 mm,5 μm) using 0.02 mol/L ammonium acetate-acetonitrile(80. 5∶19.5) as mobile phase by isocratic elution.The detection wavelength was set at 250 nm.The results showed that good linear ranges for mannose and glucose were obtained from 10.0 mg/L to 1 000 mg/L with correlation coefficients(r2) larger than 0.999.The mean recoveries were in the range of 88.1%-91.0% at spiked levels of 28.0-80.0 mg,and the relative standard deviations(RSDs) were less than 3%.The limits of detection(LODs) were 0.10 mg/L and 0.08 mg/L for mannose and glucose,respectively.The method is sensitive,accurate and reliable，and is suitable for the determination of mannan and β-glucan in the yeast cell wall samples.