Objective Measure and compare the body weight, body length and chest circumference of SPF KM, NIH and BALB/c mice. Methods We mated KM, NIH, BALB/c six times, when we got offspring, and measured them at 1d, 14d, 21d, 28d, 35d, 42d, 49d, 56d and 63d. The weights were tested at electronic balance and the body length and chest circumference were tested by ruler. Result and Conclusion KM mice were similar to NIH mice in the body weight, body length and chest circumference. But BALB/c mice had lots of differences from both of the KM and NIH mice.