Objective To study the effects of association factor on growing development and reproductive performance of experimental mice. Methods ICR mice were fed under different association factor, mating ways and crowded condition, and the number of newborn mice, delivery rates and body weight at different times were recorded. Results The reproductive performance of the 1st fetal showed no significant difference between different groups (P >0.05). And the one of the 3rd fetal was similar to the 2nd fetal, the comparison of the number of newborn mice between different groups showed no significant difference (P >0.05). The delivery rates and delivery body weight of newborn mice of group A were significant higher than the other groups (P<0.01), and the delivery body weight of newborn mice of group D were significant lower than the others (P<0.01). The body weight of group F was higher than all the other groups. The one which was significant different from group E and G at 28 days (P<0.05), just showed significant difference between group E at 35 and 42 days (P<0.05). The increasing body weight of group F were higher than all the other groups at different times, but showed no significant difference between group G (P >0.05). The increasing body weight of group F and G both showed significant difference between group E (P<0.05) during 36 to 42 days. All results of group H were significant lower than the others (P<0.01). Conclusion Association Factor may has the effect on growing development and reproductive performance of mice, and should be paid attention to during the process of feeding and managing experimental mice.