Abstract: AIM: To evaluate the quality of Chinese herb Ligusticum, a RP-HPLC method was established to separate and determine the two active constituents, ferulic acid and ligustiphenol, in plants of genus Ligusticum. METHODS: ODS column (Nucleosil-C₁₈, 7 μm) was used. MeOH—H2O (40∶60) adjusted to pH 3.6 by H3PO4 was the mobile phase with detection at 280 nm. 2-Naphthol was used as the internal standard. RESULTS: Ferulic acid and ligustiphenol were separated baselinely. The peak area ratios of the two compounds to internal standard were linear when the injection amount were from 0.27 to 4.38 μg and from 0.55 to 8.80 μg, respectively. The average recoveries were 97.3%～100.9%. Quantitive determination of the two active constituents in the rhizoma of Ligusticum from different habitats was investigated using this method. There was great difference in the quantity of the two active constituents in the rhizoma of Ligusticum from different habitats. CONCLUSION: The contents of ferulic acid and ligustiphenol in genuine drugs of Ligusticum were higher than from other habitats. The results showed that the two active constituents were as a scientific basis for evaluating the genuine drugs of Ligusticum.