Maydis Leaf Blight, caused by Bipolaris maydis, the disease on maize results not only in yield reduction but also deteriorate the value and quality of the grain. During this time the control is carried out by farmers using synthetic pesticides. But dependence on the use of synthetic pesticides has not been able to solve the problem of leaf blight disease, instead it often leads to new problems, such as the occurrence of environmental damaged. Needed an environmentally friendly alternative that is a biological control to control the pathogen. Bacillus subtilis is one of the many bacteria developed as biological agents to control plant pathogens. This study was aimed to examine the effectiveness of B. subtilis biopesticide formulation by mean of seed treatments and foliar sprays, using different concentrations and frequencies to control maydis leaf blight (MLB) disease on maize, caused by Bipolaris maydis, and to evaluate its function as a plant growth promoter. The experiments were conducted at the greenhouse and in the field using factorial design. At the greenhouse trial, seed treatment and foliar spray application at 3 weeks interval produced better result in controlling MLB, and better result on promoting maize plant growth. In the field experiment, using a concentration of 3 g/l showed a better effect on suppressing the disease and on increasing yield. Application of the formulation of B. subtilis TM4 biopesticide reduced MLB disease by 21%.