This study concerned with the destructive effect of herbicide atrazine on the the early embryonic stages of Clarias gariepinus with estimation of LC50 and corresponding terms of incubation period, hatching success and mortality rate. This adverse effect also determined on the morphological and histological structures and the corresponding different shapes of malformations and pathological effect for different organs. As well as the changes in metabolic and antioxidant enzymes, DNA damage, lipid peroxidation, endocrine disrupture as thyroid hormones and protein gene expression.