Objective To accumulate operating experience and background data for housing mice in individually ventilated cages (IVC).Methods 5 weeks old Balb /c male mice(n =80) were allocated to 8 groups(n =10), which then housed in 5 or 10 per cage in 3 IVC systems(30,50 and 70 air changes /h, respectively) and one open-top cages (OTC) shelf for 8 weeks.Body weight was assessed at the initial date and every week .By the end of the experiment, necropsy was done and organs were separated and weighed .Excelland SPSS software statistics was made to draw the growth curve, and comparative analysis of body weight and organ coefficients was performed between the groups .Results 1.The growth curves of 5-mice per cage were better than that of 10-mice per cage.2.In the IVC groups, the curves trend and fluency of 50 air changes /h were more similar to that of 5-mice housed OTC group.3.The previously mentioned differences were statistically not significant (P >0.05).4.In the liver coefficients, there was a statistically significant difference between the 10-mice housed OTC group and 5-mice housed IVC group with 30 air changes /h(P <0.05), there wasn`t any other significant statistically difference with the organ coefficients between groups (P >0.05).Conclusions Based on the results of this study, the air change frequency on 50 times per hour and keeping 5 Balb/c mice per cage is recommended as the best condition for mouse housing in IVC .