Total polyphenol content of 90 medicinal plants from Seven-Mountain area, Tinh Bien district, An Giang province was determined by photometric method with Folin-Ciocalteau reagent. The results showed that 7 samples have more than 200 mg GAE g-1, 22 samples from 100 to 200 mg GAE g-1, 35 sample from 50 to 100 mg GAE g-1, and 26 samples lower 50 mg GAE g-1 respectively. Seven extracts which contained highest polyphenol were stem of Morus alba, leaves of Euphorbia thymifolia, leaves of Excoecaria cochinchinensis, stem of Combretum latifolium, bark of Anogeissus acuminata, stem of Spatholobus parviflorus, and stem of Tetrastigma erubescens with polyphenol contents of 300.0, 281.4, 262.0, 244.6, 237.8, 221.2 and 220.0 mg GAE g-1, respectively.