Abstract: In this paper,taking the rhizosphere soil of healthy hybrid bamboo as the object and based on 25 strains Bacillus spp. obtained by dilution-plate method,the fermentation activities of the two strains of biocontrol bacteria against Rosellinia necatrix were determined by the oxford cup method and the perforating method. B2 was the optimal strain and the pot experiment showed that it had great biocontrol potential,which was identified as Bacillus cereus by morphology and physiology-biochemistry. The field tests showed that 100~200 times (volume ratio) of dilution of the bacterial inocula was used to irrigate the surface roots with 100 mL per plant and applied once in spring each year,which could prevent the occurrence of white root rot. 50~100 times (volume ratio) of dilution of the bacterial inocula was used to irrigate the surface roots and surrounding soil with 200 mL per plant and applied twice in spring and summer each year and lasted for use of three years,which could control white root rot,and the effect was better than thiophanate methyl.