Abstract: In order to select biocontrol strains with strong antagonistic to Fusarium oxysporum Schl., strain LX1 was selected by rifampicin from the peanut rhizosphere. The test results showed that strain LX1 had strong antagonistic activity against F. oxysporum on agar plates with an apparent inhibition zone. The germination rate of conidium was inhibited by 55%—78% when the culture filtrates from strain LX1 were mixed with condia solution in glass slide. Growth suppression, increasing branches of their offset and swelling in the middle and the top of the hyphae were observed with microscope. Strain LX1 was identified as Bacillus subtilis based on its morphological, staining reaction, culture traits, physiological and biochemical determination and 16S rDNA sequence. This research laid the foundation for the biological control of F. oxysporum and the development of strain LX1 for biologics.