Objective To study the efficiency of mice mutation induced by ENU. To screen and acquire the mutant mice with some new traits showing dominant heredity. Methods 33 C 57BL/6 and 18 DBA/2 male mice about 8-10 weeks old were injected intraperitoneally with a dose of ENU 100 mg/kg once a week and total three times. Mated with the same strain female mice, their progeny were screened for mutations. Results Treated males became transient sterility and the average length of sterile period was 9-13 weeks. In 1241 mice screened, 61 mice were produced with mutations, such as abnormal eyes, dwarf, white belly spot,and so on. The mutation percentage was about 5%. There were two mutation strains showing dominant heredity. Conclusion The mouse models for human diseases could be obtained by ENU-induced mutation. ENU mutagenesis on a large scale had important value for functional genome research.