An animal experiment was performed to investigate the effects of dietary cadmium on growth rates and cadmium accumulations in internal organic tissues and blood by feeding mice with dietary $cdcl_2$ additives and/or brown rice with high cadmium content as during a 12-week feeding period. The results were as follows : Mice weights decreased with increasing levels of dietary cadmium at the end of a 9-week feeding period. The weights of mice organs in the cadmium-free feeding group were higher than in the cadmium-added groups, and the weights of mice organs did not show any significant differences among feeding groups with different levels of dietary cadmium. The concentrations of cadmium in kidney and liver were much higher than in other internal organs and blood, and the next higher concentration was in the heart. The cadmium accumulation in all internal organs and blood increased with increasing dietary cadmium levels, respectively. The ratios of cadmium accumulation in organ tissues and total blood of cadmium-added groups increased with decreasing dietary cadmium levels.