To evaluate the effect of imrecoxib on CYP2C11 enzyme activity, mRNA, and protein expression, a UPLC method was established. Tolbutamide was selected as the CYP2C11 enzyme‐specific probe drug and incubated with imrecoxib in rat liver microsomes. The yield of 4‐hydroxytolbutamide was measured using UPLC to investigate the effect of imrecoxib on CYP2C11 enzyme activity. Imrecoxib (10 mg/kg) was administered intragastrically twice daily. After 1, 7, and 14 days of administration, the liver tissues were analyzed. The expression of CYP2C11 enzyme mRNA was determined using reverse transcription‐polymerase chain reaction, and its protein expression was determined using Western blot analysis. Imrecoxib concentration was inversely proportional to the production of 4‐hydroxytolbutamide in liver microsomes. Imrecoxib demonstrated a dose‐dependent inhibitory effect on CYP2C11 activity with IC50 = 74.77 μM. After administration, reverse transcription‐polymerase chain reaction showed CYP2C11 enzyme mRNA expressions were 65% (P < 0.05), 35%, and 34% of the control group, respectively (P < 0.01). Western blot analysis showed CYP2C11 enzyme protein expressions were 80, 37, and 34% of the control group, respectively (P < 0.01). Imrecoxib can reduce mRNA and protein expression of CYP2C11 enzyme in rat liver and inhibit the activity of CYP2C11 enzyme in a dose‐dependent manner. However, it does not produce clinically significant drug interactions.