Abstract:To explore the mutagenic effects of isobutyl nitrite, according to the “ Technical Specifications for the Identification of Chemical Toxicity” , Salmonella typhimurium reverse mutation test ( Ames test) and mouse bone marrow polychromatic erythrocyte micronucleus test are used for the genotoxicity of isobutyl nitrite. The strains used in the Ames experiment are the histidine-deficient strains of S. typhimurium TA97a, TA98, TA100 and TA102. There were 10 dose groups in the experiment, and the dose range is from 250 to 5 000 μg / dish, setting up negative and positive control groups at the same time. Adopting plate incorporation method to observe the number of colonies per dish. The micronucleus test has three dose groups of 11 mg / kg, 41 mg / kg and 103 mg / kg. A negative control group and a positive control group are also set up to detect micronucleus rate of bone marrow polychromatic erythrocytes. The result indicate that isobutyl nitrite did not show mutagenic effects in the Ames experiment, and in the micronucleus experiment, there was mutagenic effect on mice at 103 mg / kg.