Department of Applied Biology, Chungnam National University, Daejeon 305-764, Korea(Received on June 19, 2012; Revised on August 14, 2012; Accepted on August 21, 2012)Clubroot of Chinese cabbage by Plasmodiophora brassicae, was found to be high virulent to the Chinesecabbage, turnips and cabbage. It this study, the endophytic bacteria Flavobacterium hercynium EPB-C313,which was isolated from tissues of Chinese cabbage, was investigated the antimicrobial activity on theinactivation of resting spores and its control effect on clubroot disease by bioassay. The bacterial cells, culturesolutions, and culture filtrates of F. hercynium EPB-C313 inactivate the resting spores of P. brassicae with90.4, 36.8, and 26.0%, respectively. The clubroot was inhibited with 100% by dipping the seedlings of Chinesecabbage in culture solutions of F. hercynium EPB-C313 before planting, however the chemmical ‘fluazinam’was 91.7% in pot tests. Complex treatment were highly enhanced control efficacy with 63.7% at field of 50%diseased plants by soil incorporation with the pellet contains organic matter and F. hercynium EPB-C313,seedling drench of culture solution of F. hercynium EPB-C313 and soil drench with 10 days after planting.These results imply that the F. hercynium EPB-C313 is a very useful biological control agent of clubrootdisease of Chinese cabbage.Keywords : Biological control, Chinese cabbage clubroot, Flavobacterium hercynium, Endophytic bacteria