This study was performed to investigate the antioxidant activity of hot water extracts obtained from 10 medicinal plants.Total phenols,total flavonols and oligomeric proanthocyanidins in the extracts were determined in order to quantitate antioxidant activity.The total phenolic content measured by using a Folin-Ciocalteu assay,ranged from 8.37 to 219.24mg gallic acid equivalents(GAE)/100 g dw.The contents of flavonol and oligomeric proanthocyanidin were the highest in Chaenomelis fructus,742.88 and 1231.67 mg/ 100g dw.,respectively.