One strain of bacterium was isolated from crop ecosystem of rhizospheres and identified as Lysobacter enzymogenes. This strain exhibited strong antifungal activity against rice sheath blight pathogen, Rhizoctonia solani, mainly through the antifungal metabolite chitinase production. In addition, this strain functions as growth-promoting of rice plant. In this study, protective effect of the isolated bacterium was investigated by comparing with fungicide. The in vivo experiments demonstrated that maximum disease suppression was afforded by T1 where the culture of L. enzymogenes was applied at 2 days before pathogen infection and 33, 44 days after transplanting. At 42 and 65 days after transplanting, the sheath blight symptoms on the rice leave were reduced by 32.8% and 60.8% in T1 compared to CK. Leaf areas and leaf dry weight in T1 was also higher than other treatments. However, no significant difference was found on the number of productive tillers in rice plant among the treatments during the study.