An antimicrobial actinomycete, labelled Y-71, was selected from the putrilage soil collected from Yunnan, China. We identified it Streptomyces exfoliatus, by light microscope and SEM observation, physiological and biochemical characterization, cellwall components analysis and 16S rRNA sequence alignment. Its fermentation liquor had wide antimicrobial spectrum, effectively against the Gram-positive and Gram-negative bacteria. The antimicrobial substance was sensitive to high temperature and the 70°C condition could deprive its antimicrobial activity thoroughly. However, it was rather stable under the 2-8 pH value, and couldn’t be degraded by proteases. Based on these results, we proposed that its antimicrobial substances may not be proteins or peptides. Our research revealed the basic features of strain Y-71 and may help a lot to its further study and application, such as the isolation and purification of antibiotics.