Objective: To study the effects of Jiawei Sini powder on learning and memory ability and synaptic plasticity in prefrontal cortex of sleep deprived rats. Method: Experimental model of sleep deprivation was established by use of multi-platform method. The intervention group were fed with Jiawei Sini powder

and the dosage is 16.25 g·kg-1. The variation of learning and memory was detected by Y maze method at pre and post sleep deprivation.The changes of the ultrastructure of rat prefrontal cortex were observed by using transmission electron microscopy. Result: The percentage of correct responses of intervention group was significantly higher than those in model group (P<0.05) .Compared with the model group

the post synaptic density (PSD) in prefrontal cortex areas in the intervention group was significantly thickened (P<0.01) . Conclusion: Jiawei Sini powder could improve the ability of learning and memory in sleep deprived rats via increasing synaptic plasticity in prefrontal cortex.