Objective To study the effect of low-level 84 disinfection solution on reproductive physiology of mice. Methods 72 KM mice were randomly divided into three groups: 0.5% 84 disinfection solution group (group A), 2.0% 84 disinfection solution group (group B) and saline solution group (group C). 12 males and 12 females in each group. Corresponding medicine was given once a day by intragastric gavage for 9 weeks. The estrous cycle of female mice was observed by exfoliative cytology of vagina. After 9 weeks, The sperm abnormality test was performed, Serum samples were taken for sex hormone test by ELISA, and the histological change of testis (or ovary), heart, liver, lung and kidney were observed. Results Compared with group C, No significant difference was observed in the weight variation and serum sex hormone level in group A and B (P> 0.05). The difference of the estrous cycle of female mice was not significant (P> 0.05). No histopathological abnormality was observed. Compared with group C, There was no significant difference in the rate of sperm abnormality in group A (P> 0.05), but the rate in group B was significantly increased (P<0.05). Conclusion 0.5% 84 disinfection solution has no significant effect on reproductive physiology of mice, The concentration of disinfection solution must be strictly controlled when used.