Cadmium and Selenium are ubiquitous metals in the environment I that induces a broad range of physiological dysfunctions. The purpose of this study was to investigate the chronic effect of Cadmium (Cd) and Selenium (Se) on rats blood parameters and histopathology of the liver in the male rats. Animals were divided at random into a control and treated groups (Cd and Se + Cd), both groups were fed with the same standard food, but Cadmium chloride, and mixture of Cadmium chloride +Selenium chloride were added to the drinking water of the experimental groups. At the end of the experiments periods ( 28 days ) the animals were sacrificed , blood samples were drawn via the dorsal vena cava , Hematocrit ( Hct % ) , hemoglobin ( Hb ) , number of erythrocytes count and of erythrocytes count were determined . Liver was dissected out for histological examination. There were different alteration in the blood parameters among different treated animals (Cd and Se + Cd) and controlgroups .They differences were statistically significant (P:S 0.05) with Cd treatment. Also results showed that the positive or negative alteration of blood parameters was not significant for Se + Cd mixture treated rats group.A number of morphological change were observed in the liver , including a nuclear damage , necrosis and cell death at cadmium treatment and pronounced recovery after co-selenium supplementation indicted a considerable antagonistic effects . It can be concluded that the Cd exposure impair certain hemorheological mechanism and increase tissue damage in liver, although Selenium showed beneficial effects to some extend. In summary, this study provides data on toxic effect in rats after dietary sub lethal supplementation to heavy metals.