Cocktail method was used to evaluate the influence of ketamine on the activities of CYP450 isoforms CYP1A2, CYP2D6, CYP3A4, CYP2C19, CYP2C9 and CYP2B6, which were reflected by the changes of pharmacokinetic parameters of six specific probe drugs phenacetin, metroprolol, midazolam, omeprazole, tolbutamide and bupropion, respectively. The experimental rats were randomly divided into two group, control group and ketamine group. The ketamine group rats were given 50 mg/kg ketamine by continuous intragastric administration for 14 days. The mixture of six probes was given to rats through intragastric administration and the blood samples were obtained at a series of time-points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by UPLC-MS/MS. In the experiment for ketamine and control group, there was statistical pharmacokinetics difference for phenacetin, metroprolol, midazolam, omeprazole, tolbutamide and bupropion. Continuous intragastric administration for 14 days could induce the activities of CYP450 isoforms CYP1A2, CYP3A4 and CYP2B6 of rats.