Objective:To explore the changes of the myelin-associated oligodendrocytic basic protein(MOBP) gene mRNA and protein expression in the prefrontal cortex(PFC) of SHR/WKY and to analyze the relationship between the MOBP and the etiology and pathophysiology of Attention Deficit Hyperactivity Disorder(ADHD). Methods:The expressive levels of MOBP in the PFC of SHR and WKY were verified by using RT-PCR technique. The distribution of the MOBP in rat brains was marked by used MOBP-HRP immunohistochemistry(IHC) and the electron microscope were applied as the ultrastructural study on brain tissues. Results:The levels of MOBP gene mRNA expression(35.78 ± 6.04)% in the PFC of SHR were significantly lower than those(69.41 ± 7.43)% in the PFC of WKY rats. At the same time,there was ultrastructural difference in arrangement of the radial component in myelin between two groups. Conclusion:The less of MOBP expression in the SHR may be one of the important pathophysiological bases for ADHD.