[en] The various standard operational procedures (KOLAS, ISO, ASTM) for the determination of gamma emitting radionuclides in foodstuffs were deeply examined and compared to the KFDA standard procedure. Differences are observed in the sample preparation methods, the radioactivity measurement and data report. For the quality control (QC) of the radioactivity analysis of foodstuffs, the QC sample was prepared with Cs-137 spiked rice. The simple and practical method was developed for the self-absorption correction of gamma-ray according to the matrices with the various apparent density of foodstuffs. The foodstuffs were categorized with three classes according to its characteristics (powder, liquid and gel properties) and the sample preparation methods were improved according to its categories. The monitoring procedure to identify the contaminated foodstuffs was developed based on the uncertainty and measurement time