This study was performed to elucidate the patho-physiology of copper-poisoned rats after consecutive oral administrations of the copper sulfate. The changes in feed and water intake, gains of body weight, blood pictures and mineral compositions of several organs were observed to measure the effects of copper poisoning. 1. Compared with control group, every experimental group of which 1,000, 2,000, or 4,000 ppm/kg of copper sulfate was administered displayed a gradual decrease in feed intake in dose-dependent manners. 2. After 1,000, 2,000 or 4,000 ppm/kg of copper sulfate administration, water intake seemed to decrease in every experimental group in dose-dependent manners, but there was little statistical significance. 3. After 1,000, 2,000 or 4,000 ppm/kg of copper sulfate administration, body weight decreased in every experimental group in dose-dependent manners. 4. After 1000, 2,000 or 4,000 ppm/kg of copper sulfate administration, the PLT values and numbers of RBC and WBC significantly increased after copper sulfate administration, but the values of Hb and PCV were lower than those of control group's. 5. After 2,000 or 4,000 ppm/kg of copper sulfate administration, the levels of Cu, Mn, Fe, Pb and Zn in the liver were lowered, but the levels of Mn, Fe, Pb and Zn in the kidneys increased except Cu levels.