Abstract： Objective To observe the clinicpathological characteristics of severe focal cortical dysplasia and epilepsy-relatedcortical hamarticai tomour.And to discuss their morphological changes and correlation.Method Measure the fresh resections of epileptic focus with the same way:cut open,fixed with 10% neutral formalin solution,using paraffin sections,routine staining,special staining and immunohistochemical staining,microscopic observation in detail.They were classified according to the pathological diagnostic criteria of cortical dysplasia,diagnosing with some immunohistochemical indexes and special staining.Results Of all the 133 samples,there were 5 typical FCD Ⅱ B,6 cortical hamartoma related with epilepsy.There were severe layered disorder,typical immature neurons,great nerves,abnormal neurons and balloon-like cells in lesions of 5 FCD Ⅱ B.Except of the same lesions,there were glial neuron tumor-like proliferations.In adittional,there were mucinous background,gliosis and neurons reducing in 6 cortical hamartomas related to epilepsy.Conclusions The pathological form of severe focal cortical dysplasia is similar to that of cortical hamartomas.So they may be the continuous development of the same disease chart.