Objective To investigate effect of Ginsenoside-Rg 1 on the brain in adult rat following local ischemia. Methods The model of cerebral infarction in the territory of middle cerebral artery in rat was prepared, Ginsenoside-Rg 1 was injected to abdominal cavity with different doses, and the neurological function deficits were examined and analysed. Results In the 1st day group, no difference was found (P>0.05)in comparing every dose (50 mg/kg, 100 mg/kg, 200 mg/kg)with positive control group and negative control group. In the 3rd day group, there was no difference(P>0.05) compared with positive group, but a marked difference(P<0.05)was showed in the 100 mg/kg dose group compared with negative control group. In the 7th day group, neurological function analysis revealed great difference (P<0.05) in comparison with both pasitive group and negative group. Conclusion Ginsenoside-Rg 1 could produce effects of treatment and protection to a certain extent when it was used for local ischemia, with time-effect relationship, but with no dose effect relationship. The treatment duration should be longer, say, seven days.