A gas chromatography-mass spectrometric(GC-MS) method was developed for the determination of karanal and its isomers in detergents.Samples were extracted with methanol through ultrasonic method.The target ingredients were separated on a DB-5MS column(30 m×0.25 mm×0.25 μm) and analyzed with MS under scan mode(SCAN).Gas chromatography was used to confirm the proportion of karanal and its isomers in standard solution.The linear equations of karanal and its isomers were set up between 5 mg/L and 100 mg/L.The limits of quantitation were 0.25 mg/g.The recoveries ranged from 97.4% to 111.5%,with relative standard deviations(RSDs,n=6) of 3.7%-7.2%.This method was rapid,accurate and convenient to operate,and it was appropriate for the determination of karanal and its isomers in detergents in routine tests.