And after continuous administration of senegenin 37.0 and 74.0 mg/kg to AD rats for 30 days, the expression of Ub was down-regulated, the activity of ubiquitin ligase E3 and 26S proteasome was up-regulated, the aggregation of Aβ1-40 was inhibited, the phosphorylation level of Tau Ser396 in hippocampus neurons Aβ1-40, hippocampal, and cortical neurons was reduced (p < 0.05, p < 0.01). The gene discussed is MAPT; the disease is Alzheimer disease.