To obtain high-yield avilamycin-producing strains,low energy N⁺ ion implantation technology and screening of streptomycin-re- sistant mutants are used in the study on breeding mutation.The results show that,“saddle”region,which range is from 3×10¹⁵ to 5×10¹⁵ ions/cm²,has got better induced mutation action.It also means that the strain's resistant mutation and yield mutation closely correlate to each other,and the method of streptomycin resistant screening is feasible.We have isolated a high-yield strain SVT-45 which the productivi-ty is 195% higher than the original strain's in the rotation-flask experiments. These results showed that the ion implantation was an effective method for microbe mutagensis.