Abstract: Both S3-phage and S7-phage specially infect Streptomyces.Chitin agar,soil exact agar and improved trehalose-asparagine agar were choosed as isolation media.Three soil samples respectively from Yunnan,China and Myanmar are treated using preincubation,pretreatments and inhibitors.That the phages inhibit growth of Streptomyces on different media specially on chitin agar is proved by this study.The rate of rare actinomyces increased and the variety improved.It is a useful method to utilize phages in selective isolation of rare actinomyces.