A method was developed for the determination of hydroxylamine residues in candesartan cilexetil drugs by ion chromatography with electrochemical detection.After dissolved with dichlomethane,extracted with 30 mmol/L methanesulfonic acid solution and filtrated on an OnGuard Ⅱ RP column,the samples were injected into the instrument.The separation was performed on an Ionpac CS16（250 mm×5 mm） column using 30 mmol/L methanesulfonic acid as eluting solution at a flow rate of 1.0 mL/min.Then,a 300 mmol/L sodium hydroxide solution was added into the instrument at a flow rate of 0.3 mL/min.An integrated pulsed electrochemical detector was used for the detection,in which the electrode material is made of gold,the reference electrode is pH-Ag/AgCl composite electrode,the potential waveform is composed of six potentials of amino acid,the column temperature is 40 ℃,and the injection volume is 25 μL.The calibration curve for hydroxylamine showed a good linearity（r=0.999） in the range of 0.014 47-0.289 4 mg/L,with a limit of detection（LOD,S/N=3） of 0.007 24 mg/L and a limit of quantitation（LOQ,S/N=10） of 0.014 47 mg/L.There was a good resolution between hydroxylamine and ammonium ion.With the advantages of simple operation,high sensitivity and good reproducibility,the method could be used for the detection of hydroxylamine residues in candesartan cilexetil drugs.