Abstract: A total of 20 Kunming mice at the age of 20 days were divided into four groups randomly.The mice in different group were respectively fed with water containing 0,50,100 and 150 mg/L sodium fluoride for 120 d.The lesions of testicular tissue induced by fluoride were verified using paraffin-tissue sections.The results showed that fluoride had great effects on testicular tissue,which were as follows：the wall of convoluted tubule was disrupt,the structure of that was disordered;sperm cells and secondary spermatocytes were shed from seminaferous epithelium;vacuolated changes were found from cytoplasm and nucli of spermatocytes;cellular micronuclei frequency was higher;and deformity sperms were also found.