Abstract: OBJECTIVE: To study the mutagenicity of nitenpyram, and provide basis for safety in production and application. METHODS: Micronucleus test of polychromatic erythrocytes(PCE) in mice bone marrow, Ames test, chromosomal aberration test of Chinese hamster lung cell (CHL) and TK gene mutation assay of mouse lymphoma cell (L5178Y) were taken to examine the mutagenicity of nitenpyram. RESULTS: Nitenpyram didn't cause the increase of micronucleus rates (P>0.05). The number of revertant colonies was no more than twice the spontaneous colonies for each dosage group．Compared with the control group，there was no significant difference for chromosomal aberration rates and mutation frequency of TK gene in each dosage group(P>0.05). CONCLUSION: Mutagenic effects of nitenpyram were not detected under these test condition.

Key words: pesticide, nitenpyram, micronucleus test, Ames test, chromosomal aberration test, TK gene mutation assay