An ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for the rapid screening of 49 kinds of illegally-added chemical drugs divided into eight categories in Chinese patent medicine.The samples were extracted with acetonitrile by ultrasonic extraction,then separated on a C18 chromatographic column(2.1 mm×100 mm,1.8 μm) by gradient elution,with 0.1% formic acid-2 mmol/L ammonium acetate aqueous solution and acetonitrile containing 0.1% formic acid as mobile phases.The qualitative and quantitative analyses were performed under dynamic multiple reaction monitoring(d-MRM) acquisition mode,and external standard method was used for quantitative detection.Results showed that there were linear relationships for 49 drugs in the concentration range of 0-60 ng/mL with their correlation coefficients(r2) of 0.993 2-0.999 5.The limits of detection were in the range of 0.290-2.546 ng/g.Recoveries for the analytes at three spiked levels ranged from 86.4% to 107%,with relative standard deviations of 0.80%-3.5%.Metformin,phenformin,glibenclamide,sildenafil,tadalafil and sibutramine were detected in 5 batches(20 batches in total) of samples,with their detectable amounts of 0.076 97,1.153,0.013 41,69 500,2 400,724.0 mg/kg,respectively.With the advantages of simple pretreatment,accurate result and high sensitivity,this method is suitable for the rapid screening of illegally-added chemical drugs in Chinese patent medicine.