The aim of the study was to determine the relationship between the changes in bone metabolism and insulin-like growth factor--I(IGF-I) as well as epidermal growth factor (EGF). 10 Male S.D. rats were tail-suspended for 28 d with another 10 free active rats as control. The results showed that mineral content increased significantly, osteocalcin and albumin content had no significant change, but IGF-I and EGF content increased significantly in L3 in the suspended rats. The results suggest that although there are no change in osteocalcin and albumin content, the phenomenon of bone mineral loss still exists in the suspended rats. The increase in IGF-I and EGF content may be one of the compensation responses of the bone in the suspended rats.