We identified an endophytic fungus of Vigna unguiculata, as well as the influence of carbon sources on the production of kojic acid by the isolated fungus.This kojic acid producer was identified as Aspergillus flavus F52 according to morphological characteristics and ITS region of rDNA. The metabolite of strain F52 was obtained by recrystallization, and identified as kojic acid based on the spectral data of NMR, HR-ESI/MS and IR. The fungus was cultivated in medium containing various carbon sources, and the production of kojic acid in the fermentation broth was quantified by high performance liquid chromatography.The complex carbon source which was composed of glucose and sucrose was preferential, whereas the presence of lactose was not beneficial to the production of kojic acid. The content of kojic acid in the fermentation broth reached 24.44 g/L.Aspergillus flavus F52 might be a potent producer of kojic acid for commercial use.