Objective: To establish a method for determination of 8 kinds of organ-phosphorus pesticide residues in Chinese herbs.Method: The sample was extracted with acetonitrile and the acetonitrile extraction was concentrated.HP-17 /HP-1 double columns gas chromatograph was used for qualitative and quantitative analysis of the samples

which was verified by gas chromatograph-mass spectrometer.Result: Eight kinds of organ-phosphorus in the extract were well separated by this method.Linearities of the 8 kinds of organ-phosphorus pesticides were good（r=0.997 0-0.999 9） in ranges of 0.5-2.0 μg.The minimum determination limited range is 0.007-0.126 mg·kg-1.In the recovery test

the average recoveries ranged from 81.1% to 113.7%（RSD 2.4%-14.1%

n = 5） and from 86.8% to 116.0%（RSD 4.5%-11.7%

n = 5） in the levels of 0.5 mg.kg-1 and 5.0 mg·kg-1 of organ-phosphorus reference substances

respectively.Conclusion: This method was sensitive

accurate and precise and can be used as a reference for the national standard.