Abstract: Analytical methods of GC/FID andGC/MS for identification and determination of meperidine,an analgesic drug,and its metabolites were established.The determination of meperidinespiked in urine was shown to have a good linear relationship in the range of0.1～8.0μg/ ml urine(Y=0.4995X+0,1201,r= 0. 9996).The detection limit was 20ng/ml urine. With the developedmethods,meperidine and its metabolites in urine collected from a meperidine addict were identified anddetermined.Meperidine,normeperidine meperidinic acid in free and conjugate forms,normeperidineacid in free and conjugate forms, and acetyl-normeperidine were detected.Among these metabolites,acetyl- normeperidine was reported for the first time.