Abstract: The present invention refers to novel antibiotics, Bacileucines A and B and use thereof, which are effective as agricultural and horticultural fungicides. Bacileucines A and B are produced from the microorganism belonged to Genus Bacillus and are characterized by that they have no phytotoxicity of plant and no adverse effect on the human body, have an excellent control effect on diseases of plants such as rice plant, vegetables and green plants and cause no pollution on the environment.