This study was aimed to search the effect of barley grass (BG) on the Total Antioxidant (TAS)-Oxidant Status (TOS) and DNA damage (8OHdG) in rat with renal failure. The rats which are used in the study were randomly divided into 4 groups that each of has 8 rats: Control (C) group; injected i.p. with physiological saline once a day for 7 days, GM group; Gentamicin (80 mg/kg/day) was injected i.p. for 7 days, BG group; was given oral BG (250 mg/kg/day) for 4 weeks, GM+BG group was injected gentamicin (80 mg/kg/day) with i.p. for 7 days and BG (250 mg/kg/day) was given by oral for 4 weeks. After from the process of experiment for 4 weeks, blood sample and kidney tissue were taken. The analyses of urea and creatinine were done by autoanalyser; TAS, TOS levels by colorimetric kits; 8OHdG level by ELISA kits in serum. The kidney tissues were examined histologically. In the GM+BG group was statistically decreased levels of urea, creatinine, TOS (p<0.05) and OSI (p<0.01) compared to GM group. In the group of BG was determined the levels of TAS p<0.05 statistically increased other groups. The statistical significance was not found in the level of serum 8OHdG differences between the groups. BG decreased widespread damage to the renal glomerulus and proximal tubulus. As a result, adverse effects of high dose gentamicin application such as kidney damage can be reduced when used barley grass.