Radioprotective ginseng protein fraction was isolated from Korean white ginseng and its cytotoxic effect on CHO-K1 cells was studied by the method of measuring the relative cell survival and total cellular protein content (FRAME method). When ginseng protein at the dose of 300, 600, 900, $1200{mu}g/ml$ was treated to cells for 24 hrs, the relative survival was significantly decreased at the concentration of above $600{mu}g/ml$, indicating the presence of cytotoxic effect of the protein at certain concentration. When cellular protein content was measured after ginseng protein at the dose of 300, 600, 900, $1200;{mu}g/ml$ was treated, the amount of cellular protein was significantly reduced at the concentration above $600{mu}g/ml$ in the case of 24 hr treatment and at all concentrations including $300{mu}g/ml$ in the case of 72 hr treatment. The data suggest that the protein may inhibit cell growth, resulting in the reduction of live cells in culture. $ID_{50}$ value which is the concentration of ginseng protein that reduces the total cellular protein content to 50% of the control was calculated as 2276.86 and $1323.32;{mu}g/ml$ in groups treated for 24 and 72 hr, respectively. Since $ID_{50}$ value of above $1000{mu}g/ml$ indicates very weak cytotoxicity, the ginseng protein seems to exert very weak cytotoxic effect on CHO-K1 cells.