Abstract: AIM: To identify meperidine and its metabolites normeperidine in hair of meperidine addicts and establish the GC/MS and GC/NPD methods for determination of meperidine and normeperidine in human hair . METHODS: 5～10 mg washed hair was cut into small pieces, after hydrolysis, meperidine and normeperidine were extracted with diethyl ether and determined by GC/MS and GC/NPD. The recoveries of meperidine and normeperidine were greater than 80%, and the lower limits of detection were 0.5 ng.mg^-1 and 1 ng.mg^-1 respectively. RESULTS: Meperidine and its metabolites normeperidine and normeperidine-AC were found by GC/MS (EI, PCI) in the hair of meperidine addicts, and the hair contents of meperidine and normeperidine of 50 drug abusers were 4.8～496 ng.mg^-1 and 15.5～685 ng.mg^-1, respectively. CONCLUSION: The methods are simple, accurate and sensitive. These are adopted in routine analysis for confirmation of meperidine-abuse cases.