Rhizoma Polygoni Bistortae has been widely used as an important medicinal herb in the Far East for a few thousand years, and it has gained more recognition in the last few decades. In the present study, we used a high-performance capillary electrophoresis (HPCE) method for determination of the gallic acid (GA) in Quanshen (QS) pieces. The analysis of GA in QS pieces was successfully achieved in less than 6 min by capillary electrophoresis with UV detection at a wavelength of 290 nm. The background electrolyte was 20 mmol/L sodium borate solution (pH 9.00). The separation was performed in an uncoated fused-silica capillary (52 cm^50 lam) with an effective length of 40 cm, and the applied voltage was 20 kV. Sample solutions were injected for l0 s at an atmospheric pressure of 5 KPa. The result showed good resolution and precision (the intra-day RSD was 0.37%). The calibration curves of the standard solutions were linear in the range of 0.22-2.25 mg/mL, with correlation coefficients greater than 0.9990. The recovery of the method ranged from 100.6% to 107.9%, and the average recovery of GA was 105.9% with an RSD of 3.63%. HPCE is a powerful technology, and it is the first time to successfully apply such a method for the determination of GA in the traditional Chinese medicine.