The aime of the present study were to investigate whether the bone growth was affected by copper deficiency dur ing fetus and after birth. In this experiment the copper-deficiency rats were conducted from the beginning of conception through 45 days of postnatal life. The weights of 45-day baby rats were only one third of control group (P<0.01). The levels of copper in serum of copper-deficiency rats were lower than that of the controls also (P<0.01).Skeletal changes of radiography and pathology were observed. And there was an evidence of defective mineralization. Reontgenograpy of long bone showed osteoporosis and rarefied cortical bone in copper-deficiency rats. Light-microscopically

the cartilage cells of metaphyses became small and the number of the cells were reduced

suggesting the bone growth was stunted. After 15 days of copper supplementation

the waights of baby rats

biochemical changes in blood and reontgenograph were rapidly restoreb