Abstract： Objective To investigate the effects of sevoflurane on short-term memory impairment and the relative synaptic mechanism.Methods At 12 h,24 h and 72 h after the mice were exposed to 1.5％ sevoflurane for 1h,the spontaneous alternation and locomotor activity was assessed by Y maze,the short term potentiation (STP) were measured with extracellular recording technique in hippocampal slices.Results At 12h after administration with sevoflurane in vivo,the spontaneous alternation ( (54.7 ± 1.7) ％,P＜0.01 ) and locomotor activity (16.4 ± 1.3,P ＜ 0.01 ) decreased significantly compared with that of control group,and the population spike amplitude after induction of STP ( ( 122.3 ± 13.9) ％,P ＜ 0.05 ) decreased significantly in hippocampal slices,but there was no different at 24h and 72h.After administration with sevoflurane in vitro,the basic ( ( 83.5 ± 8.9) ％,P ＜ 0.01 ) or titanic ( ( 116.5 ± 14.9) ％,P ＜ 0.01 ) population spike amplitude decreased significantly in hippocampal slices,but the amplitude could recovery after wash-out.Conclusion Sevoflurane can impair the shortterm memory by suppressing synaptic transmission in the near future but not the long future.