ObjectiveTo determine the growth rate, organ index, blood Physiological and biochemical Parameters of germ-free KM mice during different growing Period, baby germ-free KM mice were obtained by hysterectomy form SPF KM mice and reared by hand feeding under aseptic condition. Methods(1) Weight and body size of the mice were measured at different days(from 0 to 112days; n=60; 30♀,30♂) to create a growth curve (2) The weight of the live mice and major organ size after dissection were measured at different days selected randomly (day = 8,6,112; n = 60 30♀,30♂) to determine the growth of these mice. (3) The blood Physiological and biochemical Parameters were measured by collected blood samples from the infraorbital vessels. Results(1) The weight of germ-free KM mice increased with the growing days, and the growth rate reached maximum within 1-2weeks Post-weaning. Significant difference was found between males and females(P＜0.05) after 4th week. (2) All the major organs (heart, liver, spleen, lung and brain) increased with the ages except the thyme gland, and the growth of cecum size was obvious. (3) Difference of blood Physiological and biochemical Parameters was found between males and females at the same age, and the difference types increased with the growth of mice age. ConclusionThe results of growth rate and blood physiological and biochemical parameters could provide reference for the evaluation of germ-free KM mice colony.