AIM To investigate whether ginsenoside Rg1 can reverse chronic lead-induced impairment of long-term potentiation (LTP) in the CA1 region of rat hippocampus. METHODS Neonatal Wistar rats were exposed to lead from parturition to weaning via milk of dams whose drinking water (20 mL per day) contained 0.2% lead acetate. Field excitatory postsynaptic potentials (fEPSP) were recorded and LTP was induced in the CA1 region in rat hippocampal slices on postnatal 20-25 d. RESULTS In hippocampal slices from both control and lead-exposed rats, perfusion with ginsenoside Rg1 50 μmol·L-1 for 20 min induced enhancement of fEPSP (LTP), while the amplitude of LTP in lead-exposed rats was lower than that of controls. In hippocampal slices from chronic lead-exposed rats, LTP induced by high-frequency stimulation (HFS, 1s, 100 Hz) was significantly reduced, while perfusing with ginsenoside Rg1 (50 μmol·L-1) for 20 min increased the amplitudes of LTP induced by HFS by 47.1%. CONCLUSION Rg1 can increase basic synaptic transmission and partially reverse chronic lead-induced impairment of HFS-LTP.