Objective:To study the effects of Millettia pulcha polysaccharides（YLSP） on neuronal loss and Tau（Ser202） phosphorylation in the frontal lobe and hippocampus of SAMP8 mouse.Method: The SAMP8 mice were adopted as AD model group

and the SAMR1 mice as the control group.Both groups were randomized and given the blank configuration solution.Huperzine（0.02 mg · kg-1） was given to drug-positive group and two YLSP groups were given 45

180 mg · kg-1 respectively

continuous administration for 40 days.In the frontal lobe and hippocampus

neuronal loss and Tau（Ser202） phosphorylation（pser202） were respectively detected by Nissl staining and immunohistochemical method.Result: Comparing with the normal group

the neuronal loss and the number of pSer202 positive cells of the model group were higer（P<0.01） in the frontal lobe and hippocampus.In drug-positive and YLSP groups

the neuronal loss and the number of pSer202 positive cells in the frontal lobe and hippocampus were observed obviously lower（P<0.05 or P<0.01）

comparing with the model group.Conclusion: The abnormal Ser202 phosphorylation is reduced and neuronal loss of brain is ameliorated by YLSP.