Abstract: Effects of ginsenoside Rb₁ and Rg₁ on seven kinds of central neurotransmitter receptors, α₁, α₂ and β-adrenoceptors, 5-HT, DA, GABA and M-cholinergic receptors, were measured. Results showed that no specific binding of Rb₁ and Rg₁ to any of these kinds of recptors was observed. However, 5 days after i. p. injection of Rb₁ and Rg₁ higher Bmax values were observed for the brain membranes from treated mice than those from control mice. Rb₁ and Rg₁ were also shown to increase protein biosynthesis in mouse brain. The findings may be helpful to elucidate ginseng's mechanism of central actions.