Gamma irradiation at 5 and 10 kGy was applied to Kwamegi (semi-dried Colobabis seira) for their possible hygiene quality and carried out genotoxicological safety. In vitro genotoxicological safety of each 5 and 10 kGy-irradiated Kwamegi was evaluated by Salmonella typhimurium (TA98, TA100, TA1535 and TA1537) and E. coli WP2 uvrA reversion assay, SOS chromotest (Escherichia coli PQ37) and chromosome aberration test (Chinese hamster lung fibroblast cells) in the absence and presence of an exogenous metabolizing system (S9 mix). Gamma-irradiated samples were not different from nonirradiated-control to respective in vitro tests. And in vivo micronucleus test using ICR mice (male) micronucleus was not observed. Kwamegi exposed to 10 kGy-gamma ray revealed negative results in these three in vitro mutagenetic tests and in vivo micronucleus test up to 10,000 $mu extrm{g}$/plate, respectively. The results indicated that 5 and 10 kGy gamma-irradiated Kwamegi (semi-dried Colobabis seira) did not have mutagenicity.