Abstract: The present invention relates to the Bacillus sp. strains AT-332 (NITE BP-1095) and AT-79 (NITE BP-1094) isolated from nature; and a plant disease control agent, a nematode control agent and a plant growth promoter containing the strains as active bacteria. The Bacillus sp. strains AT-332 and AT-79 strain are effective in controlling both a wide range of various plant diseases and nematode-damage and capable of promoting the growth of useful plants, due to a culture containing a secondary metabolite of the strains or cultivated and isolated live bacteria of the strains being introduced to a plant body or to the culture soil.