Objective To investigate the mechanisms of p38 Mitogenactivated protein kinase signaling pathway in cognition injury after sleep deprivation in rats. BR> Methods One hundred male SD rats were randomly divided into three groups: control group（EM>n/EM>=20），model group（EM>n/EM>=40）, inhibitor SB203580 treatment group（EM>n/EM>=40）. Sleep deprivation models were established by the modified multiple platform method. After sleep deprivation 1 day,3 days,5 days,7 days，morphological changes were observed by electron microscopy.The expressions of phosphorylated p38MAPK and interleukin 1β（IL-1β） proteins were detected with immunohistochemistry and Western blotting. The learning and memory functions were performed with Eightarm maze. Results Compared with control group,the morphous of nerve cells changed；the expressions of phosphorylated p38MAPK and IL-1β proteins increased；the learning and memory functions significantly decreased with time of sleep deprivation. Compared with model group, the morphological changes,t