Abstract: On the basis of single factor test, the extraction process of polyphenols from Populus euphratica was studied by orthogonal test through the polyphenols content deter mined by Prussian Blue spectrophotometry. From the variance analysis, the order influenced extraction of polyphenols was extraction time>ratio of solid to liquid>volume fraction of solvent>extraction temperature.The results showed that the optimal extraction conditions were 40% acetone aquatic solution as extractant, 1:7 of the ratio of solid to liquid,3 h of extraction time, 45℃ of extraction temperature and 3 times of extraction. Under above optimal conditions, it was found that the polyphenols content in Populus euphratica bark was 6.10%, the extraction rate of polyphenols was 99.03%,and the average recovery of polyphenols was 94.64%.

Key words: orthogonal test, Populus euphratica, plant polyphenols