The experiment was designed to determine the protective role of Brassica nigra seed extract on Kidney function and tissue against the negative effects induced by the drug Captopril (CPT25 and CPT50). In this experiment, 30 animals (Rats male) were used. Kidney efficiency was measured by measuring The level of urea and creatinine and level of Glutathion (GSH), Malondialdehyde (MDA) and Superoxide dismutase (SOD) in kidney tissue, as well as studying the histological effects of the drug Captopril (CPT25 and CPT50). against ،Kidney tissue and the protective role of Brassica nigra seed extract . The results showed that the treatment of animals with drug Captopril (CPT25 and CPT50) at a dose of 1.9 and 3.8 mg / kg bw for 30 days led to a significant increase in The level of urea, creatinine, (MDA), (SOD) and decrease in The level of (GSH). The treatment of animals with drug Captopril (CPT25 and CPT50) has shown Effected on kidney tissues cases the infiltration and inflammatory of inflammatory cells between the urinary tubules, the presence of hemorrhage within the kidney tissue and the renal glomeruli, and cellular degeneration of some cells of the urinary tubules. Brassica nigra seed extract improves most of the negative effects caused by drug Captopril (CPT25 and CPT50). The aim of this study is to investigate the negative effects of captopril on kidney tissues, and to identify the protective role of Brassica nigra seed extract against the negative effected of captopril on some biochemical and histological parameters. The conclusion from this study is that the drug Captopril showed an effected on the kidneys of the experimental animals, represented by the emergence of tissue lesions in the organ tissues, and through the results of the results, the protective effected of Brassica nigra seed extract against the effects of captopril was identified.