Abstract: A method of high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was developed for simultaneous determination of the residues of five opium poppy husk alkaloids in foods, such as morphine, codeine, tibane, papaverine and narcotinum. The samples were extracted by methanol (containing 5% ammonia acetate), and then analyzed by HPLC-MS/MS. The separation was carried out by a Capcell PAK C18 TYPE MGⅡ(5 μm×2.0 mm×150 mm) column, with 10 mmol/L ammonium acetate (pH 4.2) and acetonitrile as mobile phases at a flow rate of 0.2 mL/min. Multiple reaction monitoring (MRM) mode was applied, with positive ion electrospray ionization (ESI). Sample matrix-matched calibration was used to determine the residue contents by external standard. Under the optimized detection conditions, the linear ranges for morphine and codeine are 1.0-20.0 μg/L, and for tibane, papaverine and narcotinum are 0.2-4.0 μg/L, the linear correlation coefficients are all more than 0.999. The limits of quantification for morphine, codeine, tibane, papaverine and narcotinum are 7.5, 7.5, 1.5, 1.5 and 1.5 μg/kg, respectively. The recoveries of five opium poppy husk alkaloids range from 72.2% to 111.4% with the relative standard deviations (RSD) of 3.1%-8.8%. This method is simple, effective and sensitive, which is suitable for the determination and confirmation of five opium poppy husk alkaloids added in the foods illegally.