Three experiments were conducted to examine(1) dietary zinc and (2) copper requirements, and (3) interaction of dietary copper and zinc in crucian carp fed sempurified egg white diets or casein diets, reared in indoor aquaria for 88, 96, and 84 days respectively. The first in experiment 1 were fed diets containing 0, 5, 30, and 50 mg supplemental zinc/kg diet, while the fish in experiment 2 were fed diets with five supplemental copper levels of 0, 2, 4, 6, and 32 mg/kg diet. The fish in experiment 3 were given either a copper: zinc ratio of 1:1 or 1:4 containing supplemental copper levels of 15 and 150 mg/kg diet respectively. The basal diets in experiment 1 and 2 contained 2. 1 mg zinc/kg diet and 0.8 mg copper/kg diet respectively, and 8.6 mg zinc/kg diet and 1.3 mg copper/kg diet in experiment 3. The concentrations of zinc and copper in the water of all three experiments were 84 ppb and 20.6 ppb. Zinc deficiencies of crucian carp exhibited depressed growth, supressed apetite, and low feed efficiency ratio. The growth rate of the fish fed diets with no supplemental zinc were significantly low as compared to those fed diets containing 50, 30, and 50 mg supplemental zinc/kg diet were found with higher feed efficiencies than those fed diets without supplemental zinc. The activities of serum alkaline phosphatese were decreased in crucian carp with low dietary zinc intake. Red blood count (RBC) values were higher in the fish fed low zine diets than that of control fish. At the end of the experiments, the liver zinc levels were significantly lower in crucian carp fed diets contained 5 mg supplemental zinc/kg diet. The results shown that crucian carp has a zinc homestatic mechanism through regulating zinc incorporation and excretion. The light anemia were observed in crucian carp fed basal diets with no supplemental copper. RBC values were increased in the fish fed diets containing supplemental copper. Growth rate and feed efficiency ration, as well as hemoglobin (Hb) and hematocrit (Hc) values were not significantly different between the fish fed basal diet and all the fish fed diets containing supplemental copper. Liver and plasma copper levels were positively correlated with dietary copper intake. Plasma or serum glutamic-pyruvic transaminase (GPT) activities and glutamic-oxaloacetic transminase (GOT) activities were reduced in the fish fed diets containing high supplemental copper. Hepatosomatic index tended to larger with copper intake increased. Zinc had negative effects on copper absorption and metabolism for crucian carp liver copper levels were decreased in crucian carp fed high zinc diets as compared to those fed low zinc diets. Plasma iron levels were higher in crucian carp fed high copper diets than those fed low copper diets. This indicated that copper had positive effects on iron absorption and metabolism. Based upon the results of present study, the dietary requirements of dietary zinc and copper for crucian carp were found to be 50 and 4 to 6 mg/kg diet respectively.