To establish an easier and more humane treatment way, experimental rats were respectively fed 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 1.0% of D-penicillamine mixing with dietary compositions, and the proper dietary D-penicillamine dose was discussed. The results indicated that the doses of 0.3% and 0.4%of D-penicillamine effectively decreased the copper content in liver and serum of rats through promoting the urinary output of copper without side-effects. Therefore, 0.3%~0.4% was considered as the best dietary D-penicillamine dose for removing copper from rats. Also, the results showed that the metabolisms of copper and zinc in rats were not exactly similar, and there might be a precise mechanism for maintaining the hepatic zinc lever.