Abstract: To improve the suspensibility and wettability of Bacillus marinus B-9987 wettable powder(WP)and decrease the pH of B.marinus WP, the formulation of B.marinus WP was optimized by additives screening and mixture tests design. The results showed that addition of sodium dodecyl sulfate (SDS) could improve the suspension and wetting effects for B.marinus WP. Mixture design was used to determine the optimum mixture proportion for light calcium carbonate(LCC), kaolinite and SDS. The experimental data showed that the most suitable contents of SDS, LCC and kaolinite in B.marinus WP were 9.54%, 83.74 % and 6.72%, respectively. Under these conditions, predicted suspensibility, pH and wetting time of B.marinus WP was 75.15%, 8.62 and 89.40 s, respectively. Furthermore, the experimental suspensibility, pH and wetting time of B.marinus WP was 73.13%, 8.33 and 100.00 s, which were in good agreement with predicted. The optimized B.marinus B-9987 WP without energy-intensive milling even can meet the standards of wettable powder, which greatly reduces the cost of production.