A pressurized capillary electrochromatographic（pCEC） method was developed for the determination of the main anthraquinones,including rhein，emodin，aloe emodin，chrysophanol and physcion in root of Polygonum cuspidatum.The separation was performed on a reversed phase EP-100-20/45-3-C18 column（total length of 45 cm,effective length of 20 cm，diameter of 100 μm，ODS packing inside for 3 μm）.The mobile phase was composed of 20 mmol/L NaH2PO4（pH 4.7）-acetonitrile（15∶85） at a flow rate of 0.04 mL/min.Under the optimum conditions including running voltage of +5 kV，UV detection wavelength of 254 nm，the limits of detection（S/N=3）were in the range of 0.60-2.54 μg/mL for rhein，aloe emodin，emodin，chrysophanol and physcion，respectively,and the linear detection ranges were 3.57-162.68 μg/mL with correlation coefficients not less than 0.998 2.The established method was used in the analysis of anthraquinones in polygonum cuspidatum with good results.The recoveries at three spiked levels ranged from 91.1% to 101.2%，with relative standard deviations（RSD） of 0.03%-3.6%.