Objective:To establish a HPLC method for the determination of baicalin in Shangsuyu Spray.Methods:A Shim pack CLC ODS column was used. The mobile phase consisted of NH 4H 2PO 4 buffer (3.0) methanol (50∶50). The detective wavelength was 276nm.Results:The linear range was from 1.08 to 20.60?g/ml, r =0.9999. The recovery of the added sample was 100.5%. RSD was 2.5%. This method was easy to operate with accurate result, high sensitivity and good reproducibility.Conclusion:The method can be used for the determination of the contents of baicalin in Shangsuyu Spray.