Objective: To study the effect of Qingkailing in model mice by measuring learning and memory ability and the expression of β-amyloid protein in brain tissue. Method :Male KM mice were randomly divided into 6 groups: Control group; Model group; L-QKL group (20 g ·kg-1); M-QKL group(40 g ·kg-1); H-QKL group (80 g ·kg-1) and Nim group (0.03 g ·kg-1). All the mice were administrated by ig with drugs or water in the same volume for 30 days. AD model of mice was established by ip scopolamine. The Morris water maze was used to observe the learning and memory ability for the model mice. Biochemical methods were used to determine the content of β-amyloid protein in brain tissue. Result: :Qingkailing could significantly improve the memory of model mice compared with the control group

Qingkailing could decrease the content of β-amyloid protein in the brain tissue obviously. Conclusion: Qingkailing could improve the ability of learning and memory of model mice

and its mechanism might involve in reducing the level of β-amyloid protein in brain tissue.