This study was designed to investigate the effects of calcium supplementation on calcium metabolism in seven healthy college women, aged from 19 to 21 years old. For this purpose, metabolic studies were conducted for two weeks. During the first week, the subjects ate experimental diet which nutrients composition was similar to their usual intake. And during the consecutive second week, they ate the same experimental diet supplemented with 500mg of calcium daily. The results were summarized as follows ; 1) Fecal excretion of calcium increased significantly (P<0.05), but urinary excretion of that did not show any change after supplementary intake of calcium. 2) Mean apparent calcium absorption was 28.5% and retention was 182mg/day when subjects ate the experimental diet without calcium supplementation. Calcium retention was significantly ate the experimental diet without calcium supplementation. Calcium retention was decreased to 24.1% by additional intake of calcium. 3) Phosphorus balance did not show any change after additional intake of calcium. 4) Serum calcium level was also not changed by additional intake of calcium. 5) Serum calcium level increased significantly(P<0.05) but serum phosphorus level did not show any change after additional intake of calcium. The above results showed that supplementation of 500mg calcium daily can be helpful to increase calcium retention as well as the peak bone mass in young women eating usual Korean diets.