One strain F05 which had better antagonism for American ginseng rust rot was obtained from continuous cropping ground, and its fermentation had been preliminarily studied, more over the research can further determine the optimum composition. The single factor and uniform design were used to optimize the formulation medium. The identified formulation was powder of cornstalks 3.7206%, (NH4)2HPO4 0.5312%, MgSO4 0.0355%, K2HPO4 0.0400%. The bacteria number was 1.57 x 10(9) per milliliter culture solution.