Abstract: Six main tertiary alkaloids, (—)-tetrahydrocolumbamine(A), (±)-tetrahydropalmatine (B), (+)-corydaline (C), (—)-tetrahydroberberine (D), tetrahydrocoptisine(E) and(+)-glaucine (F) were separated by HPLC within 25 min ona column (25 cm×2.dmm) of Nucleosil 10₁₈ equipped with a YWG-C₁₈ guard column; elution was effected at 0.8 ml/min with an isocratic mobile phase of 70% MeOH, and the elute was monitored at 280 nm.External standards were used for the determination. The calibration curves for the first five alkaloids are rectilinear in the range of 0～1.7 μg with CV of 0.95～1.24%. In contrast, the calibration curve for the 6th alkaloid is linear in the range of 0.3～1.6 μg with CV up to 3.05%, which does not pass through the origin.The individual alkaloids in 6 Yuanhu samples, cultivated in different localities and processed with different methods were determined. The alkaloid Contents of the samples with vinegar steamed as well as the control samples extracted by boiling water, and percolated with 60% EtOH were also presented. The results of the proposed HPLC method are in good agreement with those of the TLC-densitometry.