Abstract: To develop an UPLC-UV method for the determination of aristolochic acid A in the aerial and underground parts of Asarum, an AcquityUPLC^TM HSST3 column (50 mm×2.1 mm ID, 1.8 μm) was used with the mobile phase of acetonitrile-0.1% FA and eluted in gradient mode. The flow rate was 0.5 mL·min^-1, the detection wavelength was 251 nm, and the column temperature was 40 ℃. The calibration curve was linear in the range of 18-1 450 ng of aristolochic acid A with correlation coefficient of 0.999 9 and the minimum detective concentration was 18.25 ng·mL^-1. The method developed is accurate and reproducible, and can be applied in the determination of aristolochic acid A in Asarum.