A method was established for the determination of 508 pesticide reisdues in Panax notoginseng by liquid chromatography-tandem mass spectrometry(LC-MS/MS).The samples were extracted by modified QuEChERS method,followed by the clean up of d SPE extraction.The extract was determined by LC-MS/MS in multi reaction monitoring(MRM) mode,and quantified by the internal standard method.There were linear relationships for the 508 pesticides in the range of 0005-04 mg/L with limits of detection(LOD) of 0005-01 mg/kg.Except for 8 pesticides,the recoveries for other 500 pesticides at spiked level of 100 μg/kg were in the range of 502%-117%with relative standard deviations(RSD) not more than 15%,in which,the recoveries for 468 pesticides were in the range of 70%-120%.With the advantages of simplicity,rapidness,good sensitivity and accuracy,the method could meet the requirements for multiple pesticide residues analysis,and is suitable for the determination of 508 pesticide residues in Panax notoginseng.