Objective To develop a method for the determination of ketamine analogues in hair samples by liquid chromatography quadrupole linear ion trap mass spectrometry(QTRAP LC-MS/MS).Methods 20 mg of washed and dried hair was added to 1 mL extracting solution and then prepared using an ultrasonic extraction with frozen pulverization method.After centrifugation and purification with membrane,the supernatant was separated in a ACQUITY UPLC? HSS T3 column with gradient elution,finally tested with multiple reaction monitoring for the detection of 10 ketamine analogues.The above method was applied for quantitative analysis of ethylfluamine,F-norketamine and tiletamine in 20 positive samples.Results When the concentration ranged from 0.01 to 2.00 ng/mg,there was good linearity for 10 ketamine analogues with the correlation coefficients over 0.99.The recoveries ranged from 89.1％to 106.1％,and the matrix effects were between 88.3％and 106.0％.Among the 20 positive samples,the contents of ethylfluamine,F-norketamine and tiletamine in hair ranged between 0.02～8.35 ng/mg,0.01～0.94 ng/mg and 0.02～10.93 ng/mg,respectively.Their mean values were 1.59 ng/mg,0.28 ng/mg and 2.69 ng/mg.Their medians were 0.40 ng/mg,0.19 ng/mg and 2.11 ng/mg.Conclusion The established method was simple,efficient,reliable and suitable for the determination of ketamine analogues in hair.The data provided reference for the drug control and forensic science practice.