In this study it was found that the enzyme activities of diseased ginseng contributed greatly on the development of its root-rot disease. The 4i sensed ginseng showed higher activities of $alpha$-amylase, p amylase, invertase, catalase, and cellulase than those of fresh one. The increased enzyme activities of diseased ginseng were originated in those from infected pathogens, which showed a proportional relationship between enzyme activities and root-rot power of them. The increases of enzyme activities during incubation of inoculated ginseng could be considerably depressed by controlling culture environments as to temperature below 4$^{circ}C$, pH 8-9, and relative humidity about 60%, Some metal ions and organic reagents also inhibited the enzyme activities of diseased ginseng. But their inhibitory effects were not so great that they might be used to protect the disease.