To determine the effect of r-irradiation on the microorganisms destruction and the changes of general constituents of Ginseng Powder, three samples were analyzed at 1st and 3rd month after r-irradiation. The results were as follows: 1. Total bacterial counts were decreased during storage as the irradiation dose increased. It seems that about 300 Krad was satisfactory to the regulation of ginseng powder. ($5.0 imes 10^4 /g$) 2. Coliform group was also decreased during storage as the irradiation dose increased. Coliform group was not detected at the irradiation dose higher than 500 Krad. 3. Total bacterial counts and coilform group were in proportion to the content of moisture in ginseng powder. 4. The contents of moisture, ash, crude protein, crude lipid and total sugar in ginseng powder during storage had nearly no changes. 5. The content of reducing sugar in ginseng powder during storage had the increasing tendencies as the irradiation dose increased. 6. The content of amino-nitrogen in ginseng powder during storage had the decreasing tendencies as the irradiation does increased.