The present invention is a method for preparing a biocontrol formulation by the following steps. A Streptomyces bacterium is selected simultaneously with superior sporulation ability, chitinase activity and antagonistic effectiveness against plant fungal pathogens by culturing with fungal pathogens, wherein the selected Streptomyces bacterium is cultured on a chitin-limited plate to assess the ability of sporulation and chitinase activity, and the Streptomyces bacterium with superior sporulation ability is the strain with producing powder-like and maturity form spore chains. Spores from the selected bacterium is collected. The obtained spores are taken as a seed inoculum. Then the seed inoculum is cultured to directly yield a broth medium containing at least 10⁹ viable spores/ml which the spores contained in the broth medium are well suspended. The biocontrol formulation is obtained. The present invention further provided a biocontrol formulation containing a high concentration of Streptomyces spp. spores.

Claims data not available