Abstract: A method was developed for residue determination of picloram in wheat plants,grain,flour,wheat bran and soil by using high performance liquid chromatography coupled with tandem mass spectrometry(HPLC-MS/MS).The residues of picloram in wheat and soil samples were extracted by acetone and cleaned up by primary secondary amine(PSA) connected with graphite carbon column,and then analyzed by HPLC-MS/MS in multiple reaction monitoring(MRM) mode via positive electrospray ionization with an Agilent ZORBAX SB-C18 as the analytical column.Results showed that at fortified levels of 0.01 to 1 mg/kg,the average recoveries of picloram in wheat plants,grain,flour,wheat bran and soil were from 78.9% to 97.9%,and RSD were from 3.6% to 9.6%.The method is simple,rapid and characterized with acceptable sensitivity and accuracy to meet the requirements of the pesticide residue analysis.The method is applicable to confirm the residues of picloram in wheat and soil.