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.