Abstract: OBJECTIVE To establish a method for rapidly qualitative and quantitative detection of phenformin hydrochloride, glibenclamide and pioglitazone hydrochloride illegally added in traditional Chinese medicines for antidiabetics by UPLC-Q-TOF-MS. METHODS The Aglient ZORBAX SB C₁₈(2.1 mm×100 mm, 1.8 μm) column was used, with the mobile phase of methanol-10 mmol·L^-1 ammonium?acetate(0.1% formic acid) by gradient elution. Electrospay ionization(ESI) source was applied and operated in the positive ion mode. Qualitative and quantitative detection were analysized by retention time, DAD, mass spectra, and tandem mass spectra as four aspects information. RESULTS Phenformin hydrochloride, glibenclamide and pioglitazone hydrochloride were all detected illegally added in five batches capsules. CONCLUSION This method is specific, sensitive, easy to operate and can be used to detect the phenformin hydrochloride, glibenclamide and pioglitazone hydrochloride illegally added in traditional Chinese medicinal preparation for antidiabetics.