Ｏｂｊｅｃｔｉｖｅ　Observing the effects of ginsenoside Rg1(Rg1) on sevoflurane anesthesia induced cognitive dysfunction in neonatal mice.　Methods　Seventy two C57BL/6J mice at postnatal day 6 were randomly divided into the following four groups(n=18) according to the random number table: control with normal saline(NS) group(Con+NS group), control with Rg1 group (Con+Rg1 group), sevoflurane anesthesia with NS group (Sev+NS group) and sevoflurane anesthesia with Rg1 group (Sev+Rg1 group). The mice were subjected to 3% sevoflurane plus 100% O2 or 100% O2 2 h daily for 3 consecutive days, respectively. The mice in different groups were given intraperitoneal injections of NS (1 ml·kg-1·d-1) or Rg1 (10 mg·kg-1·d-1) half an hour before anesthesia, respectively. The Morris Water Maze test was performed at postnatal day 31－37 with 12 mice in each group. The hippocampus tissue was collected after the behavioral test to measure the expression level of postsynaptic density 95 protein (PSD-95). ELISA was used to test the ATP and reactive oxygen species(ROS) levels in the hippocampus immediately after the last anesthesia at day 8 with 6 mice in each group.　Results　Compared with the Con+NS group[(35.6±4.5), (28.3±3.5), (21.9±2.4) s], the escape latency in morris water maze test of Sev+NS group at postnatal day 35－37 were increased significantly[(45.7±8.1), (41.9±8.8), (35.1±12.4) s](P<0.05). Compared with the Con+NS group 4(8, 2), times across the platform in morris water maze test of Sev+NS group were decreased significantly 2(6, 0)(P<0.05). Compared with the Con+NS group [(100±6)%] (P<0.05), the expression level of PSD-95 of Sev+NS group [(77±6) %] were decreased significantly. Compared with the Con+NS group[(100±4)%], the ROS level of Sev+NS group[(121±11)%] were increased significantly(P<0.05). Compared with the Con+NS group[(100±6)%], the ATP levels of Sev+NS group[(82±7)%] were decreased significantly(P<0.05). In addition, for Sev+Rg1 group, the escape latency and times across the platform in morris water maze test, the content of PSD-95, the ROS and ATP levels were not significantly different with Con+Rg1 group(P>0.05).　Conclusions　Rg1 can alleviate sevoflurane anesthesia induced hippocampus-dependent long-term cognitive dysfunction in neonatal mice, which is associated with the oxidative stress, mitochondrial dysfunction and synaptic plasticity in hippocampus.