Abstract: [Objective] To establish a high-performance liquid chromatography （HPLC） method for the determination of eprinomectin content in an emulsion preparation of eprinomectin. [Methods] The chromatographic column was C18 （150×4.6 mm, 5 μm）, mobile phase was acetonitrile-water （70：30）, flow rate was 1.0 mL/min, detection wavelength was 245 nm, injection volume was 20 μL, and column temperature was 25 ℃. [Results] Eprinomectin showed a good linear relationship within the concentration range of 0.1-20 μg/mL. The standard curve equation was C=1.6015A-0.00206, r=l.000 （n=5）, RSD of the method was between 0.72% and 1.40%, and the average recovery was between 96.5% and 100.5%. [Conclusion] This method has the advantages of high sensitivity and accuracy, good reproducibility, simplicity and rapidity, and can be used for the quality control of emulsion and other preparations of eprinomectin.