In the present study, a bacterial strain producing caproic acid, which was isolated and purified from Luzhou-flavor Liquor Pit Mud, and characterized by morphological, physiological and molecular biological methods. Results showed that the strain had the typical characteristics of Bacillus clone, acid- producing capacity as strong as 4.1g/L. Analysis of its 16SrRNA gene in Ribosomal Database through online tools supported that the strain was Lysinibacillus sp in genus Lysinibacillus. The present study was the first report that Lysinibacillus sp has capacity for producing caproic acid.