The purpose of this study was to investigate the effect of calcium intake on lipid contents and enzyme activities in rats of different ages. Lipid levels in serum and liver and GOT, CPK and LDH activities in serum were compared in rats of different ages(4 weeks and 10 months) that were fed various levels of calcium(50, 100, 200% of requirement)for 3 weeks. Body weight gain and feed efficiency ratio were significantly higher in young rats than in adults. Serum calcium level was increased by elevation of calcium intake levels were decreased. Liver phospholipid and triglyceride levels in the high-cal-terol and triglyceride levels were decreased. Liver phospholipid and triglyceride levels in the high calcium group were significantly lower than those in other groups. Serum GOT and LDH activities of adults were significantly higher in low-calcium group than those in adequate/high-calcium groups. However, serum CPK activity of adults was significantly higher in high-calcium group than that in low/adequate-calcium groups. The results of this study suggest that adequate calcium intake may have protective effects ont he alteration of lipid and enzyme activity in rats.