In this study, total phenolics contents, total flavonoids contents and antioxidant activities of four different solvent extracts of Cleome gynandra L. seeds were determined. Total phenolics contents of the extracts prepared were determined with Folin-Ciocalteau reagent according to the method using gallic acid as a standard phenolic compound. The total flavonoids contents of the extracts prepared were determined by UV spectrophotometry and rutin was used to make the calibration curve. Antioxidant activities of the extracts prepared were evaluated applying DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, total reducing power and hydroxyl ion scavenging assay. The decreasing order of total flavonoids contents is acetate ethyl extract (CAEE) > methanol extract (CME) > petroleum ether extract (CPEE) > dichloromethane extract (CCE) in four different solvent extracts. The decreasing order of total phenolics contents is CME > CAEE > CPEE > CCE. The decreasing order of antioxidant activities is CME > CAEE > CPEE > CCE in all the methods which is in conformity with total phenolic content. The results clearly demonstrate that acetate ethyl extract has highest total flavonoids content, but methanol extract has highest total phenolics content and strongest antioxidant activities. It can be used to prevent oxidative stress related diseases and can be stored as food supplement. So further investigation of individual isolated compounds and their antioxidant activities in vivo and different antioxidant mechanisms is needed.