Objective To detecte the expressions of phosphorylated p38 MAPK (p-p38 MAPK), Bax and Bcl-2 in the cerebral cortex of hyperlipidemia rats after cerebral ischemia-reperfusion (I/R) injury and the effect of SB203580 on the expressions of p-p38 MAPK, Bax and Bcl-2, to explore the effect of p38 MAPK activation on the expressions of Bax and Bcl-2 in hyperlipidemia cerebral I/R injury.   Methods After the hyperlipidemia model was established, the rats were randomly divided into 3 groups: sham operation group, operation group (I/R) and SB203580 treatment group (SB+I/R), with 10 rats in each group. The focal cerebral I/R model in hyperlipemia rats was established with thread embolism of the left middle cerebral artery. The neurobehavioral score was used to observe the symptoms of neurobehavioral injury. The 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to detect the volume of cerebral infarction, and the TUNEL staining was used to observe apoptotic cells. The relative expression levels of p-p38 MAPK, Bax and Bcl-2 were analyzed by immunohistochemistry.   Results Compared with the sham group, the infarct volume, apoptosis index and neurobehavioral score of rats in the I/R group increased significantly, and the expressions of p-p38 MAPK and Bax increased significantly, and the expression of Bcl-2 decreased significantly (P<0.05). Compared with the I/R group, rats in the SB+I/R group had less brain damage, the infarct volume and the apoptosis index were significantly reduced, the expressions of p-p38 MAPK reduced significantly, Bax expression decreased while Bcl-2 expression increased. The differences were statistically significant (P<0.05). Neurobehavioral scores were lower in SB+I/R group than in I/R group, but the difference was not statistically significant.   Conclusion In the process of cerebral I/R injury in hyperlipidemiarats, activation of p38 MAPK can regulate the expression of Bax and Bcl-2.