In order to investigate biochemical effects of ginseng saponin on microbial enzyme activity, Aspergillus oryxae-143 and Aspergillus niger-40, which were selected from various sources of samples and were the highest enzyme producing mold strains, were grown in the medium containing various saponin concentration (0mg%, l0mg%, 50mg%, l00mg%, 150mg% and 300mg%). The enzyme activity (amylase, protease) was found most active when the saponin was added in the culture media with the concentration of l0mg%∼l00mg%. But it seemed that the action of microbial enzyme was inhibited by adding more than 300mg% of saponin.