This study was aimed to search the effect of wheatgrass on the Total Antioxidan (TAS)-Oxidan Status (TOS) and DNA damage in rat with diabetes. The rats used in the study were randomly divided into 4 groups that each of has 10 rats: Control group; 1 ml single dose phosphate-citrate buffer injected i.p (pH: 4.5), Diabetes group; 45 mg/kg single dose streptozotocin injected i.p., Wheatgrass group; was given oral wheatgrass (10 ml/kg/day) for 6 weeks, Diabetes +Wheatgrass group; 45 mg/kg single dose streptozotocin injected i.p. and wheatgrass (10 mlikg/day) was given by oral during 6 weeks. After the process of experiment during 6 weeks, blood sample and pancreas tissue were taken. The analysis were done of blood glucose levels, TAS, TOS levels by colorimetric kits; DNA damage by ELISA kits in serum. The pancreas tissues were examined histopathologically. In the group of Diabetes+Wheatgrass was determined that the levels of glucose levels (p<0.001),TOS (p<0.05) and OSI (p<0.01) statistically decreased and heal histopatolojical compared to diabetes group. In the group of Wheatgrass was determined that the levels of TAS p<0.05 statistically increased from other groups. The statistical significance were not found in the level of serum 8OHdG differences between the groups. The beta cells were seen to increase in the group receiving wheatgrass for therapeutic purposes.As a conclusion, it was determined that wheatgrass strengthened the anti-oxidant defense system and reduced the glucose level in diabetic rats.