Abstract: It has been well documented that ginsenoside Rb₁ and Rg₁ are important activeprinciples of ginseng.In the present studies,Rb₁ and Rg₁ were found to prolong the duration ofneuronal life and provided partial protection against the excitotoxic effect of glutamate in primaryhippocampal cultures. Since excitotoxic neuronal injury of glutamate is considered to be caused by theincrease of intracellular Ca²⁺ concentrations, the effects of Rb₁ and Rg₁ on Ca²⁺+i elevated byglutamate were measured in cultured hippocampal cells using Fura-2/AM as a calcium indicator。 Theresults showed that Rb1 and Rg1 could selectively inhibit the high level glutamate(500 μmol·L^-1)induced increase of Ca²⁺i,suggesting that the neuroprotective activities of Rb₁ and Rg₁ weremediated by blocking calcium over-influx into neuronal cells.