OBJECTIVE：To study the effects and mechanism of panaxadiol （PD） on Tau protein phosphorylation in the SH-SY5Y cells transfected with APP gene（APP-SH-SY5Y）. METHODS ：The target of PD and non-receptor tyrosine kinases Fyn was verified by molecular docking. SH-SY 5Y cells were cultured in vitro ，and the APP-SH-SY 5Y cell models and green fluorescent （GFP）-SH-SY5Y cell model （control cell ）was constructed. The expression of Aβ1-42 was detected so as to verify the success of APP-SH-SY5Y cell model. Taking GFP-SH-SY 5Y cells as control ，the effects of 5，10，20，30，40 μmol/L PD and 125，250， 500，1 000，2 000 nmol/L PP 2（Fyn inhibitor ，positive control ）on the survival rate of APP-SH-SY 5Y cells were detected by CCK-8 assay after treated for 24 h，so as to confirm the optimal concentration. The concentration of Ca 2 + ，the ratio fophosphorylated Tau protein （p-Tau）/Tau，phosphorylatedn Src（p-Src）/Fyn and phosphorylated glutamate receptor 2B（p-GluN2B）/ GluN2B were detected in APP-SH-SY 5Y cells after trated with the optimal concentration of PD and PP 2 for 24 h. RESULTS ：The results of molecular simulation docking showed that PD could target Fyn protein. Compared with GFP-SH-SY 5Y cells ，the protein expression of Aβ1-42 in APP-SH-SY 5Y cell were increased significantly （P＜0.01）. The optimal concentration of PD and PP 2 were 20 μmol/L and 500 nmol/L. The 20 μmol/L PD and 500 nmol/L PP 2 could increase the survival rate of the cells and reduced the concentration of Ca 2+，the ratio of p-Tau/Tau ，p-Src/Fyn，and p-GluN 2B/GluN2B. CONCLUSIONS：PD can reduce the the phosphorylation of Tau protein through inhibiting Fyn/GluN 2B signaling pathway.