A method was developed for the simultaneous detection of six known impurities in captopril tablets. Methods Gradient elution was employed with Waters μ Bondapak? column 300 mm × 3. 9 mm 10 μm used as the chromatographic column column temperature was set at 45 ℃ and the mobile phase consisted of phosphoric acid-water 0. 06 ∶ 100 A and phosphoric acid-water-acetonitrile 0. 06 ∶ 50 ∶ 50 B with gradient elution 0 ~ 5 min 90% A 5 ~ 40 min 90% A →60% A 40 ~ 55 min 60% A flow rate of 1. 5 mL detection wavelength of 210 nm and injection volume of 20 μL. Results The method demonstrated good specificity effectively separating captopril from adjacent impurities and known impurities. Moreover captopril and the known impurities showed a good linear relationship between concentration and peak area r>0. 999 5 . The method also exhibited good precision accuracy and durability. The impurity profiles of the self-made captopril tablets and the reference formulation were basically consistent and all batches of samples met the quality standard requirements. Conclusion The method possesses good specificity accuracy precision and durability and can effectively separate the six known impurities making it a reasonable and reliable method for quality control of captopril tablets.