Abstract: Aim:To develop an HPLC method for the determination of azithromycin hydrochloride and its related substances.Method:Dikma ODS column and 40 ℃ of column temperature.The mobile phase: 0.1 mol/L ammonium dihydyogen phosphate solution(adjusted pH to 6.5 by triethylamine)and acetonitrile(70∶30).The flow rate was 1.0 mL/min and UV detective wavelength was 215 nm.Results:Some impurities were obviously separated under the chromatographic system described above.The calibration curves were linear between 10.0～50.0 mg/mL(r=(0.999 8)).The average recovery of adding sample was 99.97%.Precision and inter-day RSD were 0.50%(n=6)and 0.79%(n=6).Conclusion:The method is proved to be quick,simple and sensitive.