To investigate the effects and possible mechanisms of ginsenoside Rb₁ on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced dopaminergic neuronal injury and behavioral abnormalities in mice.In vitro isolated and cultured mouse dopaminergic neurons were treated with MPTP (10 μmol/L) and different doses of Rb₁ (10,20,40 μmol/L),and neuronal morphology was observed.A Parkinson's model was constructed by intraperitoneal injection of MPTP (30 mg/kg) into C57B/L6 mice,and different doses of Rb₁ (10,20,40 mg/kg) were given by gavage,and mice were subjected to behavioral tests using open field test and rod climbing test;Western blot was used to detect striatal TH,CaMKII,FP1 and Bcl-2 expression.The results showed that different doses of ginsenoside Rb₁ significantly improved MPTP-induced neuronal injury compared with control group.Ginsenoside Rb₁ treatment significantly improved the behavioral abnormalities in MPTP-induced PD model mice.Ginsenoside Rb₁ significantly upregulated the reduction of TH and Bcl-2 caused by MPTP,and had no significant effect on the reduction of CaMKII and FP1 expression.Ginsenoside Rb₁ had significant ameliorative effects on MPTP-induced neuronal injury and behavioral abnormalities in mice,and the mechanism may be related to the reversal of TH and Bcl-2 expression.