A method for the determination of the related substances of atorvastatin calcium was established.An optimal HPLC method was set up.The known impurities were qualified and quantified by standard method.Other impurities were calculated by the main component self-contrasted method.A Wondasil C18 column (4.6 mm×250 mm, 5 μm) was applied.The mobile phase was acetonitrile-tetrahydrofuran-ammonium acetate buffer with a gradient elution at a flow rate of 1.0 mL·min-1 and the detection wavelength was set at 244 nm.The column temperature was 30°C, and the volume of injection was 20 μL.The resolutions between atorvastatin and adjacent impurities (impurities B and C), and between the known impurities were greater than 1.5.The limits of quantification of impurities A, B, C, D, E were 30, 40, 40, 20, 10 ng.The calibration curves of five known impurities were linear in the self-concentration range (r>0.9901, n=5).The average recovery rates (n=9) were 98.5%, 111.3%, 91.5%, 106.6%, 106.5%; RSDs were 4.8%, 4.1%, 4.7%, 7.3%, 6.4%.The method is reproducible and accurate for determination of the related substances in atorvastatin calcium according to methodol. validation.