Three phenylpropanoids (ferulic acid, chlorogenic acid, and caffeic acid) are simultaneously separated and determined within 13 min by a new capillary electrophoresis method using 15 mmol/L sodium borate (pH 8.71) as run buffer. The optimum conditions for the separation as well as the analytical characteristics, such as the calibration graph and limit of detection (LOD) for the determination of these three compounds, are studied. The linear range for the determination of ferulic, chlorogenic, and caffeic acid is 5.0 approximately 70.0, 8.0 approximately 112.0, and 9.0 approximately 64.0 microg/mL, with the LOD as 1.5, 2.25, and 6.0 microg/mL, respectively. The method, which is very simple, rapid, and of requisite sensitivity and reproduction, is satisfactorily used for the separation and determination not only of ferulic, chlorogenic, and caffeic acid in Cimicifuga foelida Li and its preparation (Yin-huang-han-pian), but also of ferulic acid and chlorogenic acid in Ligusticum chuanxiong hort. and Angelica sinensis (Oliv.) Diels.