ObjectiveTo explore the microscopic character and clinical pathological feature of focal cortical dysplasia (FCD).Methods51 cases were collected from January 2015 to September 2018 in the 988th Hospital of the Joint Logistics Support Force of the People’s Libereation Army. Pathology with FCD of their diseased brain tissue was classified according to the classification standard by the International Anti-Epilepsy Union (ILAE) in 2011. Epileptic seizure characteristics were analysed in different types.ResultsFCD I was 23 cases (45.1%). FCD II was 11 (21.6%). FCD III was 17 (33.3%). Ia was the most common type (23.5%, 12/51). Neurons were arranged into microcolumnar structures in Ia. NF expression in immunohistochemistry was characteristic. It was close to the neuron like line or waterfall. The second type was Ⅲa (15.7%, 8/51). Hippocampal sclerosis was given priority to CA4 area pyramidal cells to reduce or disappear. Three types all happened in bilateral cerebral hemisphere. There was no statistical difference. Temporal lobe was significantly more than frontal lobe. More than 50% of the cases occurredepilepsy before the age of 18. The main manifestation was partial onset seizures and secondary body stiffness clonus. The onset age and history of epilepsy in patients with FCD Ⅲ were earlier than those in the other two types. On image the positive rate of I type was 78.3% and that of Ⅱ and Ⅲ was both 100%.ConclusionFCD is a common pathological feature of epilepsy patients. Carefully pathologic examination is the premise of accurate classification of each subtype. Ⅲ type is different from Ⅰ and Ⅱ type in epileptic seizures.