Abstract: Bacillus subtilis T429 was confirmed to be highly bacteriostatic to rice fungus diseases in previous study. Fermentation broth of B. subtilis T429 was granulated by spray-drying technology to develop new bacterial pesticide formulation. Single factor test and experiment with four-factor and three-level orthogonal were carried out to optimize spray-drying condition. Results showed that the optimum conditions were inlet air temperature 120℃, the feed flow rate 720 mL/h, atomization caliber 1 mm, atomization pressure 0.1 MPa, hot air flow 30 M³/h. The number of viable cells of products reached to 8.61×10⁹ cfu/g under the optimal conditions. These data helps development of new pesticide formulation of B. subtilis.