OBJECTIVE: To develop a method for simultaneous determination of catalpol and leonuride in Mongolian medicine Cymbaria dahurica. METHODS: HPLC method was adopted. The determination was performed on XSelect HSS T3 C18 column with mobile phase consisted of acetonitrile-1.0% phosphoric acid water solution (gradient elution) at the flow rate of 1 mL/min. The column temperature was set at 40 ℃, and the detection wavelength was set at 203 nm. The sample size was 10 μL. Established method was adopted to determine the contents of catalpol and leonuride in 7 batches of C. dahurica samples. RESULTS: The linear range of catalpol and leonuride were 0.17-3.4 and 0.25-5.0 μg (r≥0.999 5). The detection limits were 3.57 and 4.72 ng, respectively. The quantitative limits were 12.24 and 41.98 ng, respectively. RSDs of precision, stability (24 h) and reproducibility tests were all lower than 2.0% (n=6). The average recoveries were 93.0%-97.3% (RSD=1.9%, n=6) and 92.1%-97.9% (RSD=2.4%, n=6). The contents of catalpol and leonuride in 7 batches of samples were 0.53-0.81 and 0.79-1.25 mg/g, respectively. CONCLUSIONS: The established method is rapid, simple, stable and reliable, and can be used for simultaneous determination of catalpol and leonuride in C. dahurica.