This study was performed to investigate the effect of dietary calcium level on cadmium and lead toxicity in rats. Fifty-four male rats of Sprague-Dawely strain weighing 152$pm$12g were blocked into 9 groups according to body weight, and were raised for 30 days. Nine experimental diets different with cadmium(0%, 0.04%), lead (0%, 0.071%) and calcijm(0.5%, 1.0%, 1.5%) levels were prepared. The results are summarized as follow. Weight gain, F.E.R.(food efficiency ratio), and weights of liver, kidney and femur were lower in cadmium exposed groups than those of heavy metal free groups. Weight gain F.E.R. and ash weight of lead groups were lower than those of heavy metal free groups. But, these were increased with increasing dietary calcium level. Cadmium and lead concentrations in blood, liver, kidney and femur were lower in rats fed 1.5% calcium than 0.5% calcium diet. Fecal cadmium and lead excretions were remarkably increased in 1.5% calcium groups, and cadmium and lead retention rates were decreased in 1.5% calcium groups. Metallothionein concentrations in liver, kidney and small intestine were higher in rats exposed to cadmium and lead. Calcium content in blood, femur and daily urinary and fecal calcium excretion were decreased by cadmium and lead additions, and increased in 1.5% calcium groups. Creatinine clearance were decreased with cadmium administratino and calcium addition. In conclusion, weight gain and organ weights were decreased with cadmium or lead administration. But, cadmium administration was more toxic than lead adminstration. Cadmium or lead toxicity was alleviated by increasing dietary calcium level. Especially, lead toxicity was alleviated in proportion to dietary calcium level