Objective：To investigate the neurologic impairment induced by sedative midazolam and its mechanism. Methods：72 rats were divided into normal saline control group，midazolam group，dexmedetomidine group，each group contained 24 rats. Neuron specificity enolization enzyme（NSE），central nervous specificity protein （S100β），cell death receptor level of Fas，escape latency，swimming speed，through the original number were compaied in three groups. The pathological sections of NSE，S100β and Fas were analyzed. Results：In midazolam group，the levels of NSE，S100β and Fas were higher，the escape latency was longer，and the number of passing through the original platform was less（ P<0.05）. Conclusion：Midazolam has a significant effect on neurological impairment and learning and memory functions.