Curcumin is a pigment found in Indian saffronspices, also known as turmeric. The aim of this study is to investigate theantioxidant effect of curcumin, a phytochemical, on the blood tissue of rats. In the study, 24 Wistar rats were 8 weeks old,randomly divided into 2 groups which were the control group and theexperimental group was fed with curcumin supplement. Curcumin supplemented groupwas fed at 300mg/kg/day curcumin dissolved in corn oil by oral gavage for 12days. 24 hours after the last feeding, TAC (Total Antioxidant Capacity) and TOC(Total Oxidant Capacity)  were analyzedin blood samples. In curcumin supplemented group TAC decreased significantlythan control group (p<0,05). When the TOC is examined, in curcuminsupplemented group TOC was evaluated statistically higher than in the controlgroup (p<0,05). Results of the study show that curcumin strengthens theantioxidant defense system.