Objective To study the genotoxicity of sodium dehydroacetate (Na-DHA). Methods Five strains of Salmonella Typhimurium (TA97a, TA98, TA100, TA102 and TA1535) were used with the presence and absence of S9 in bacterial reverse mutation test. Bacteria were treated with Na-DHA at the dose levels of 1 667,556,185,62,21 μg/plate. Both negative and positive controls were set. The number of revertant colonies per plate were counted. Kunming mice used for micronucleus test were treated with Na-DHA at 549.0,275.0 and 137.0 mg/kg BW by gavage twice a day with a 24 h interval. The femurs of mice were removed at 6 h after the second gavage. The numbers of red blood cell(RBC), polychromatic erythrocytes(PCE) and micronucleus(MN) were observed. The PCE/RBC and MN/PCE(the incidence of micronucleus) were calculated. Chinese hamster ovary(CHO)cells were treated with Na-DHA (2 000,1 000,500 μg/ml) in the presence and absence of S9 for 6 or 24 h. Three hundred well-spread metaphases per group were scored, following the incidence of chromosomal aberration recorded. Results No significant difference in the number of mutant colonies of TA97a, TA98, TA100, TA102 and TA1535 between the treated groups and the negative control group (P>0.05).The incidence of micronucleus in each dose group was not significantly different from that in the negative control group (P>0.05).No significant difference in the incidence of CHO cell chromosome aberration between the dose group and the negative control group (P>0.05). The mutant colony number, the incidence of micronucleus and the incidence of chromosome aberration in the three tests were significantly lower than that in the positive control groups, with statistically significant differences(P<0.01). Conclusion No genotoxicity of Na-DHA was found in vivo nor in vitro.