An antagonistic bacterium named SQR11 which possessed strong ability to suppress tobacco bacterial wilt caused by Ralstonia solanacearum (abbreviated as RS) was isolated, and the biological control effect of successive application of bioorganic fertilizer produced by this strain on controlling tobacco wilt was studied. Based on physiological and biochemical determination and the 16S rDNA sequence analysis, strain SQR11 was identified as Bacillus amyloliquefaciens. Biological control efficiency of the bioorganic fertilizer applied during the successive batches of pot experiments were 47%, 69% and 89%, respectively. Results from the third pot experiment indicated that plants showed symptoms when the number of pathogens in the rhizosphere soil reached 2×105 cfu/g dry soil, and the incidence of symptoms were accompanied with the increasing number of RS. The pathogens were effectively controlled when the number of antagonistic bacteria in the rhizosphere soil reached 2×107 cfu/g dry soil. The number of the antagonistic bacteria in the stems of the healthy tobacco was 4×104 cfu/g plant tissue, while the number of the pathogens in the same position was 1.5×102 cfu/g plant tissue; the number of the antagonistic bacteria in the stems of the diseased tobacco was only 6×103 cfu/g plant tissue, whereas the number of the pathogens in the same position reached 3×103 cfu/g plant tissue. The results also indicated that application of the bioorganic fertilizer could also promote tobacco growth. In conclusion, successive application of bioorganic fertilizer produced by strain SQR11 could significantly control the tobacco bacterial wilt caused by Ralstonia solanacearum by extensive colonization of SQR11 in the tobacco roots.