Central pontine myelinolysis(CPM) is rare, with fewer than 30 cases reported in children. It is characterized by demylinated regions throughout the brain and which are most prominent in the pons. The original patients studied were all chronic alcholics, but subsequently the condition has been found in children and in other patients with electrolyte abnormalities, most notably hyponatremia which had been corrected rapidly. CPM symptoms include spastic quadriparesis, pseudobulbar palsy, and acute changes in mental status leading to altered levels of consciousness, coma, or death. This condition was originally thought to be uniformly fatal, but there have been recent reports of survival accompanied by varying degrees of residual neurologic deficit. We experienced a case of central pontine myelinolysis in a 1-year-old girl in 1998. On admission, she had right hemiphegia and developmental delay. She suffered from hyponatremia a year prior to admission. We performed brain MRI and other studies. She was diagnosed with CPM though brain MRI.