, a plant pathogenic fungus, can cause serious yield and quality losses in the winter lettuce field. For biological control of , soil-born microorganisms that inhibit the mycelia growth of and were isolated from diseased soil. Among the isolates, bacterial isolate, GG95, which was identified as according to the morphological, physiological characteristics and by 16S rRNA similarity, showed the highest level of inhi- bitory activity. The growth conditions for GG95 were optimized in TSB media (pH 7) by culturing at 28ºC for 24 hrs. Maltose or fructose and peptone were selected as the best carbon and nitrogen sources, respectively. Greenhouse experiment was performed to test effectiveness of GG95 in the control sclerotinia rot. Drench application (1 × 10 cfu/ml, 3 times) of the bacterial culture broth to lettuce showed an effectiveness value of 88%, suggesting that GG95 would be a promising biocontrol agent for control of sclerotinia rot.