Abstract: With infected phage-sensitive producing strains by phages isolated from waste-liquid of glutamic acid fermentation, the phage-resistant mutants were isolated with spontaneity mutation. The high-producing strains were screened by simple and convenient method with mixed UV and NTG treatment. It is effective method for screening phage-resistant and high-producing strain because the processing is simple, convenient and reliable. With this method, we got the high-producing and phage-resistant strain which increased 21.4%than the control in shaking-flask culture.