This study was performed to investigate the effects of different levels of Cu(0,6,60 ppm ) and kinds of lipid(corn oil, sesame oil or butter) in the diet upon lipids metabolism and Cu & Fe contents in weanling rats. The results obtained were summarized as following : 1) Food consumptions, total body weight gains and F.E.R.s showed no significant differences among groups with different dietary Cu levels and the kinds of lipid. 2) Weights of liver, hind limb muscle, kidney, spleen and epididymal fat pad showed no significant differences among groups. 3) The contents of total lipids and total cholesterols in serum, hind limb muscle were significantly higher in low Cu groups than in control and high Cu groups. But the contents of total lipid in liver were significantly lower in low Cu groups than in other groups. 4) The contents of total lipid and total cholesterol in serum, liver and total lipid in muscle were significantly higher in butter groups, but the contents of total cholesterol in muscle were significantly lower in butter groups. 5) The Cu concentrations in serum, liver, muscle and feces were significantly higher in high Cu groups than in control and low Cu groups. The Fe concentrations in serum tended to be lower and those in muscle were significantly higher in low Cu groups.