The purpose of the study was to develop a new process to manufacture ginseng extract containing saponin aglycon of high concentration. The process to transform saponin glycosides to saponin aglycon was analyzed by high performance liquid chromatography (HPLC). GCK-1 (open cultured mixture for 1 day at $42^{circ}C$) had the highest content of protopanaxadiol (0.662%). However, other mixtures (GCK-2, 3, 4, 5, and 6) had less than 0.152% in the content of protopanaxadiol. In case of fermentation by inoculation of Bacillus natto, BNG-5 (B. natto inoculated mixture for 5 days at $42^{circ}C$) showed the highest content of protopanaxadiol (0.364%). Other mixtures (BNG-1, 2, 3, 4, and 6) also showed the high content of more than 0.2% in protopanaxadiol. B. natto inoculation or open culture fermentation with soybean transformed ginseng saponin glycosides into saponin aglycon.