Abstract: During the isolation of antabonistic actinomyces from soil in Hainan province, we solved the issues of a contamination by bacteria and fungi. In study, we tested the best concentration of effective convenient, cheap inhibitor K2Cr2O7 that can impure antabonistic actinomyces, and the soil were treated separately by heating high temperature 120℃ and drying in air. The best soil store time of isolating the antabonistic actinomyces was also did. The results showed that the right concentration K2Cr2O7 is 50μg／ml, The antabonistic actinomyces strains is 30~40 when the soil diluting concentration in 10-3~10-4,the efficiency is best. The soil staying in air after a week’s isolated more antabonistic actinomyces strains than that Heated by high temperature 120℃.