OBJECTIVE： To establish a method for the determination of related substances in anastrozole. METHODS： HPLC was performed on the column of Welch Materials XB C18 with mobile phase of acetonitrile-water （35 ∶ 65，V/V） at a flow rate of 1.0 mL/min， detection wavelength was 210 nm， column temperature of 25 ℃， and the injection volume was 20 μL. RESULTS： Only one impurity （impurity A） was detected in anastrozole， the linear range was 0.1-1.6 μg/mL （r＝0.999 6）； limit of quantitation was 0.1 μg/mL， limit of detection was 0.02 μg/mL； RSDs of precision， stability and reproducibility tests were lower than 2％； recovery was 98.95％-105.29％ （RSD％＝1.78％，n＝9）. CONCLUSIONS： The method is simple， accurate， and can be used for the determination of related substances in anastrozole.