Abstract: For screening the safe and effective drugs of leek maggots,to compare the 20%of imidacloprid·Phoxim EC,1.8%of AvermectinsEC,2%of granular imidacloprid GR and 40%of PhoximEC,to select a suitable and safety pesticide of leek production by filling root test,the security clearances pesticide residues of four kinds of pesticides were determined.The result showed that the four kinds of pesticides had better control effect and lasting period on leek maggots,the drug control effect was achieved 70%after 21 days of test.The sampling determination of pesticide residues results at safety interval showed that the residue of 2%of granular imidacloprid GR was overproof at 22.5 kg/hm2,the other three kinds were within the scope of security.Considering the control effect,keeping strain effect and pesticide residues situation,the 1.8%of AvermectinsEC,the 2%of granular imidacloprid GR and the 40%of PhoximEC can be alternate used,to be as the prevention and treatment of leek maggots.It should be appropriate to reduce the 2%of granular imidacloprid GR dosage in the practical.