The genotoxicity of water extract of Bojungikkeehapdaechilki-tang was tested by In Vitro Chromosome Aberration Test. Bacterial Reverse Mutation Assay and Micronucleus test according to OECD Guidelines and KFDA Guidelines. The obtained results were as follows : 1. Chromosome Aberration Test: In Vitro Chromosome Aberration Test of Bojungikkeehapdaechilki-tang extracts was carried out using cultured Chinese hamster lung cells in the presence and absence of metabolic activation system(S-9 mix). No significant changes in the number of aberrant metaphases having structural and number of aberrations were detected in Bojungikkeehapdaechilki-tang extracts treated groups. 2. Bacterial Reveres Mutation Assay: Bojungikkeehapdaechilki-tang extracts was evaluated for its potential to induce reverse mutation in the histidine auxotroph strains of Salmonella typhimurium such as TA100, TA1535, TA98 and TAl537 and the tryptophan auxotroph strain of Escherichia coli WP2 uvrA. No significant changes in the number of revertant colonies compared to its negative control were detected in Bojungikkeehapdaechilki-tang extracts treated groups against all 5 strains. 3. Micronucleus test: Micronucleus test of Bojungikkeehapdaechilki-tang extracts were performed using specific pathogen free 7-week old male ICR mouse. No significant changes in the number of micronucleated polychromatic erythrocytes among 2000 polychromatic erythrocytes compared to negative control were detected in all Bojungikkeehapdaechilki-tang extracts treated groups. In summarized above-mentioned results, it is concluded that Bojungikkeehapdaechilki-tang extracts have not genotoxicity against In Vitro Chromosome Aberration Test, Bacterial Reverse Mutation Assay and Micronucleus test.