The relationship between caeruloplasmin, a metallo-enzyme with oxidase activity, and plasma copper concentration was investigated in camel. In the first experiment, five camels and five cows were fed with a similar basal diet during six months. They received oral trace element during 3 months. The supplementation had no effect on plasma copper concentration and caeruloplasmin activity in the cows. In contrast, these parameters were lower in camel but increased significantly during supplementation period. The linear correlation coefficient between copper concentration and caeruloplasmin (Cp) activity was 0.87 and 0.69 in cows and camels respectively. The increase of the mean caeruloplasmin activity in supplemented camels was more important compared to the correspondent bovine activity over the range of copper concentration investigated. In a second experiment, four groups of 5 camels received one injection of copper and zinc (IM-group), an oral supplementation with copper sulphate (Cu-group), or zinc sulphate (Zn-group), and no supplementation (control-group). Copper plasma and caeruloplasmin activity increased significantly in the IM and Cu-groups during the supplementation stage. The highest linear correlation coefficients plasma Cu/Caeruloplasmin activity were obtained in IM and Cu-groups (0.84 and 0.79 respectively). In both experiments, the non-linear regression model improved the observed correlation between plasma copper and ceruloplasmin activity in camels.