This study investigated the effect of InJinORyungSan on the nephrotoxicity in rat treated with cyclosporin A. Control group were injected with cyclosporin A alone. whereas test group were injected with cyclosporin A and InJinORyungSan extract. In the control group, blood urea nitrogen(BUN), serum creatinine(S-Cr) and renal lipid peroxidation(LPO) level were significantly increased, but renal superoxide dismutase(SOD) activity was significantly decreased. In the kidney of control group, the destruction of distal convoluted tubules(DCT) and proximal convoluted tubules(PCT) were observed in renal cortex, lymphocytes and fibroblast were appeared in the portion of DCT destruction. However, in the test group, BUN, S-Cr and renal LPO level were significantly decreased as compared with control group, on the other hand, renal SOD activity was significantly increased. In the kidney of test group, the destruction of DCT and PCT were repaired as compared with control group. These results demonstrated that InJinORyungSan. can be attributed to recovery from nephrotoxicity, We consider that activated SOD by InJinORyungSan suppress renal LPO or production of free radicals induced by cyclosporin A.