||In this study, the cellular and non cellular antioxidant and free radical scavenging properties of the methanol and ethyl acetate extract of Cassia arereh leaves were evaluated. The antioxidant and free radical scavenging activity of the plant extracts and the standard (ascorbic acid and gallic acid) were assessed through DPPH radical, hydroxyl radical, nitric oxide scavenging activity and reducing power at various concentrations ranging from 1.62 to 200 mg/ml. For cellular antioxidant assay, we evaluated the haemolysis and the haematoprotective effect of Cassia arereh against hydrogen peroxide-mediated cytotoxicity of red blood cells (RBCs) induced with CuSO4/H2O2. Total polyphenol and flavonoid content of extracts were also determined using colorimetric methods. DPPH assay showed IC 50 values of 4.27 Plus or Minus 0.9 and 3.21 Plus or Minus 0.55 mg/ml respectively for methanol and ethyl acetate extract, instead of 12.5 Plus or Minus 2.99 ug/ml for standard. Methanol extract (IC50 = 41.597 Plus or Minus 7.46 mg/ml) had a significantly higher reducing power than the ethyl acetate one (IC50 = 238.89 Plus or Minus 26.56 mg/ml). The reducing power of the methanol extract was found to be not significantly different from standards. Our results showed a non significant decrease in the nitric oxide radical production due to the extracts compared to ascorbic acid or gallic acid. It was also found that, the methanol extract (IC50 = 17.06 Plus or Minus 0.82 mg/ml) was significantly more effective than that of ethyl acetate (IC50 = 76.34 Plus or Minus 3.4 mg/ml) as hydroxyl radical scavenging activity. Both extracts induced haemolysis of sheep RBCs in a dose dependant-manner. Incubation of RBCs with extracts before exposing them to CuSO4/H2O2 reduced the hydrogen peroxide-mediated cytotoxicity of RBCs respectively by 30.71 and 34.75 %, for methanol and ethyl acetate extracts after one hour. The antihaemolytic activity decreased with time for all the tested products. These results demonstrate the antioxidant properties of Cassia arereh and reveal that methanol is the best extractant for antioxidant agents of this plant.