Abstract: Bacteria CHB101 was obviously antagonistic to Sclerotinia sclerotiorum through dual culture method, producing an inhibitory belt up to 1.12 cm in width. Microscopically observed, the hyphae were altered in morphology, including necrosis of the hyphal wall, concentration and leakage of the cytoplasma, production of microconidia on the side of the hyphae. On water-agar plate, CHB101 inhibited the germination of sclerotium. The higher the concentration of CHB101, the better the efficiency was. The culture solution without CHB101 was not significantly antagonistic to the hyphal growth of Scerotinia sclerotiorum.