For the screening of gamma-irradiated grains, domestic rice, glutinous rice, barley, and wheat were irradiated with 0.1, 0.3, 0.5, 0.7, and 1.0 kGy and screened using the DEFT/APC (Direct Epifluorescent Filter Technique/Aerobic Plate Count) method. The log DEFT/APT units increased with the dose increment in all samples, whereas the log APC unit decreased gradually. For rice, barley, and wheat, unirradiated and irradiated samples with below 0.3 kGy had 2.0 or lower logarithmic units, whereas those with 0.5 kGy or higher had 2.0 or higher logarithmic units. For glutinous rice, the sample irradiated with 0.5 kGy showed 1.92 logarithmic unit and those with 0.7 kGy or higher had 2.0 or higher logarithmic units. These results suggest that if the grains show 2.0 or higher logarithmic units, they could be assumed to have been irradiated at a dose level of at least 0.5 kGy. In conclusion, grains could be easily screened through the DEFT/APC method.