Rice is one of the major diets in many countries, particularly in Thailand.   Although most rice cultivars have whitish kernel, some variants have a red color.  Red rice (Oryza sativa L) contains various benefit nutrients such as vitamins, γ-oryzanol, β-carotene, tocopherol and anthocyanin.  These substances play important role as antioxidants which can eliminate free radicals and reactive oxygen species.  However, the antioxidant activities of red rice extract has not been fully elucidated. Therefore, this study investigates the monomeric anthocyanin, total phenolic compounds and antioxidant activities of red rice extract.  Red rice was extracted with 75% ethanol.  The monomeric anthocyanin and phenolic compounds were determined by pH differential method and Follin Ciocalteu assay, respectively. In addition, DPPH radical scavenging activity and ferric reducing antioxidant power assay were used to determine antioxidant activities of red rice extract.  The results showed that total anthocyanin was expressed in 11.1875±1.00 µg per gram rice and phenolic compounds were expressed in 1.507±0.01 mg gallic acid per gram rice basis.  Red rice showed a reducing power 1.097±0.012 mg ascorbic acid per gram rice. At 300 µg/mL concentration of red rice extract showed the highest antioxidant activity at 93.00±3.66% and 0.065 mg/mL IC50 for DPPH radical assay.  These results demonstrated that red rice might be used as a natural antioxidant which could be applied to supplement products for medical treatment in the future.