Abstract: OBJECTIVE To establish a method using the correction factor to determine the content of the impurity D in atorvastatin calcium. METHODS An optimal HPLC method was set up to determine the concentration of impurity D in atorvastatin calcium. The column was Agilent ZORBAX SB-C₈(4.6 mm×250 mm, 5 μm) and Agilent Eclipse XDB-C₈ (4.6 mm×250 mm, 5 μm). The mobile phase A consisted of acetonitrile-tetrahydrofuran-buffer(3.9 g·L^-1 citric acid solution adjust with ammonium hydroxide to a pH of 5.0)(21∶12∶67), mobile phase B consisted of acetonitrile-tetrahydrofuran-buffer (3.9 g·L^-1 citric acid solution adjust with ammonium hydroxide to a pH of 5.0) (61∶12∶27), gradient elute. The detection wavelength was 244 nm and the flow was 1.5 mL·min^-1. The column temperature was 35 ℃ and the injection volume was 20 μL. Then, used the slope of linear equation to determine the correction factor between impurity D and atorvastatin calcium. RESULTS The relative retention time between impurity D and atorvastatin calcium was 1.96, and the relative correction factor was 0.94. And there was no difference between the results determined by the external standard method and the self contrast and correction factor method. CONCLUSION The method using the correction factor between substance being examined and impurity to determine the content of impurity D in atorvastatin calcium is available.