Nile tilapia(Oreochromis niloticus)is one of the lean fish species, and has been known to be a preferable raw material in seafood processing field.As an oxidant, ozone has been gradually used as an antimicrobial additive for direct contact with foods, but there are no special regulation and labelling rules in some countries and regions to date.It is necessary to evaluate the safety of Nile tilapia fillets treated by ozone-water.In this paper, an acute oral toxicity test in SD rats and genetic toxicity test in KM mice were used to evaluate the acute toxicity and the genetic toxicity of Nile tilapia fillets.The results showed that the maximum tolerated dose in SD rats was more than 15 g/kg, the maximum value for cfu of bacterial reverse mutation of TA97, TA98, TA100 and TA102 strains in the 5 dose groups was 156±10 that is less than 2 times of the minimum value for cfu of bacterial reverse mutation of TA97, TA98, TA100 and TA102 strains in positive control groups(1 773±83), with or without S9 metabolic activation system, as well as the repeated assay.Therefore, the result of Ames assay was negative.The micronucleus rates of high, middle and low dose groups were(0.40‰±0.88‰)(♀)/0.40‰±0.83‰)(♂), (0.60‰±0.89‰)(♀)/0.80‰±1.29‰)(♂)and(0.80‰±1.09‰)(♀)/(0.60‰±0.89‰)(♂)respectively.Moreover, the micronucleus rates of control group are(1.20‰±1.29‰)(♀)/(0.40‰±0.89‰)(♂).The results of bone marrow micronucleus test showed that there was no significant difference between the three dose groups and control group(P>0.05).The results of chromosome aberration test showed that chromosome aberration rates of mouse tests were 0.2%, 0.2% and 0.1% respectively, and there was no significant difference between the three dose groups and control group(P>0.05).The results of chromosome aberration test were negative.The research results showed that all of the Ames assay, bone marrow micronucleus test and chromosome aberration test were negative, there was no genetic toxicity of the tilapia fillets treated 30 min by 4.5 g/mL ozone-water which belonged to non-toxic class.