The favorable condition for the growth and antagonistic production of a Paenibacillus kribbensis PS04, a biological control agent,by single factor experiments was presented in this study. The results showed that the best carbon source was sucrose,the best nitrogen was NaNO3. The best composition of the media contained: sucrose 3%, NaNO3 0.15% and K2HPO4 0.1% by the orthogonal experiment. Subsequently the culture conditions were optimized and the results showed the medium initial pH was 7-8, the culture temperature was 30 ℃, the quantity of medium was 100 mL in a 1 000 mL flask, the culture cycle was 84 h, and the rotation speed was 180 r/min respectively.