This study aims to identify a Bacillus strain HNA3 isolated from the rhizosphere soil and characterize its broad antagonistic capacity towards various plant pathogenic fungi,and to optimize the conditions for the fermentation and the bioactive component separation,therefore,to establish a solid basis for developing the HNA3 strain into a promising bioactive agent with a broad spectrum of antifungal activity.In the present work,the classification status of the HNA3 was identified through morphological observation,16S rDNA sequence and the order of species-unique genes arrangement analysis.The spectrum and capacity of the HNA3’s antifungal activity was identified by the plate dual-culture antagonistic experiment and the antimicrobial inhibition rate,respectively.The flask shaking fermentation and acid precipitation method were used to determine the optimal conditions for the HNA3’s antimicrobial compound production and separation.By using the methods of surface activity examination and the analysis on the arrangement of candidate function genes and sequences,the basic properties of the bioactive antimicrobial compound were determined.The results showed that the HNA3 was identified as Bacillus amyloliquefaciens,and the BPY was the appropriate medium for HNA3’s culture growth,as well as for the production of bioactive antifungal compound.It was also found that the bioactive antifungal compound existed in the HNA3’s culture filtrates and it could be separated through acid precipitation.Further more,the bioactive compound could be ascribed to the category of lipopeptide and possessed the properties of high stability and stress resistance.In conclusion,the strain HNA3 demonstrates a broad spectrum of antifungal activity,and indicates a promising application prospective by developing it into a type of spraying,agricultural microbial fungicides in the future.