Objective:To evaluate the inhibitory activity of Sanqing Jiangtang decoction and chemical constituents on alpha glucosidase enzyme and to exploit the bioactive constituents.Method: The samples were prepared by macroporous adsorptive resins（JT-1-JT-13）.Glucose oxidase method and starch tolerance test experiments were adopted to evaluate the inhibitory activity of Sanqing Jiangtang decoction and its different separated fractions.Result: It was found that fractions（JT-1

JT-3

JT-6

JT-7）

separated from Sanqing Jiangtang decoction

mainly contributed to the inhibitory activity.JT-7 showed the most significant activities in the experiments.Conclusion:Glycosides and alkaloid may be the principle effective substance in the active fraction.