Abstract: AIM To explore the possible mechanism of the protective effect of ginsenoside Rg1 on dopamine induced apoptosis in PC12 cells. METHODS Flow cytometric assay was performed to quantify the apoptotic cells and detect the positive percentage of Bcl 2 and Bax proteins in PC12 cells. The expression of bcl-2 and bax mRNA was identified by reverse transcription polymerase chain reaction (RT-PCR). The CPP32 activity was measured by fluorescent spectrofluorometer. RESULTS Dopamine induced apoptosis in PC12 cells was inhibited by pretreatment with 10 μmol·L^-1 Rg1. Simultaneously, the expression of Bcl-2 protein and mRNA were increased, and the Bax protein and mRNA were decreased. The activation of CPP32 was inhibited after pretreatment with Rg1. CONCLUSION Rg1 protects against dopamine induced apoptosis in PC12 cells and this effect might be attributed to its regulation of the ratio of Bcl-2 to Bax and its inhibition of the activation of CPP32.