Objective To establish a method for the determination of forsy thin in Baohe Oral Liquid by HPLC.Methods The determination was carried out on a Diamonsil C18 column,with mobile phase of acetonitrile-water(29∶71) at room temperature.The flow rate was 1.0mL?min-1 and the detective wavelength at 277 nm.Results The calibration curves was linear in the range of 0.068~ 0.340 ? g(r=0.9996).The average recovery rate of tested sample was 99.7 %(RSD=2.1 %).Conclusion The method was specific,accurate and precise.It can be used for the quality control of Baohe Oral Liquid.