Abstract: OBJECTIVE To develop a UPLC-MS/MS method to determine ibuprofen, didofenac sodium and indometacin illegally added in traditional Chinese medicine preparation. METHODS The analysis was performed by a UPLC-MS/MS system of Waters ACQUITY UPLC/Quattro Premier, with BEH-C₁₈(2.1 mm×100 mm, 1.7 μm) column. Multiple-reaction monitoring(MRM) was performed to identify and quantify ibuprofen, didofenac sodium and indometacin, which were extracted with methanol by ultrasonic. RESULTS Three linear calibration curves were obtained with r²≥0.996 7. The precision of the method were showed by RSD (n=6) ranged from 1.7% to 4.7%. The recoveries were determinated at three concentrations and ranged from 95.1% to 104.2%. The ranges of LOQ were from 4.0 μg·mL^-1 to 11 μg·mL^-1 and the RSDs (n=9) of inter-day precision were from 1.7% to 4.1%. CONCLUSION The method is specific, simple and fast to detect ibuprofen, didofenac sodium and indometacin illegally added in traditional Chinese medicine preparation.