Abstract: [Objective] We used ultrasonic to treat soil samples to isolate rare actinomycetes strains. [Methods] We collected and suspended soil samples from mix tropical-rain-forest in Xishuangbanna. Farther, we treated the soil suspension with ultrasound for 10 to 120 s and used the plate dilution method to isolate actinomycetes. After got pure colonies, we sequenced their 16S rRNA gene sequences and calculated to put in phylogenetic analysis. The isolates were identified to the genus. We treated 10 kinds of common and identified Streptomyces with 1-5 min using ultrasonic, and then were cultured to measure their survival rate. [Results] The soil suspensions treated with different times by the ultrasonic, actinomycetes gradual increased in the number and types. Ultrasonic treating of known Streptomyces with 0-5 min, there was no significant effect on the survival number of Streptomyces. [Conclusion] The ultrasonic treating with soil suspensions for 40 s can significantly increase the total number of actinomycetes and the types of rare actinomycetes. Thereby, it is an economic and simple method to apparently increase the types of rare actinomycetes in the isolation.