This study was performed to investigate the effect of the Panax ginseng C. A. Meyer on the growth and production of aflatoxin by Aspergillus flayus ATCC 15517. Asp. fiavus with 10$^6$ conidia was incubated at 30$circ$C for 7 days on YES broth containing 0.1%, 0.5%, and 1.0% of ginseng extract. After incubation, dry mycelial weight, pH, and production of aflatoxin were investigated. The results were as follows:There was no significant difference in dry mycelial weight by the addition of 0.1% and 0.5% ginseng extract. However, it was decreased to the rate of 13.7% by the addition of 1.0% ginseng extract in 7 days. pH changes in cultures were similar regardless of the concentration of ginseng extract. The pH values decreased to minimum in 5 days and again increased. Aflatoxin production was reduced as the concentration of ginseng extract increased. When compared to the control, the production of total aflatoxin significantly reduced to 56.7%, 54.0%, 53.3% in the media of 0.1%, 0.5% and 1.0% of ginseng extract, respectively. No significant difference was observed among ginseng extract groups.