The auther has attempt to study the propagating mechanism of the excitement, which can be thought as the origin of the epileptic convulsion. The action potential has been recorded from cerebral cortex, basal ganglia, nucleus of midbrain and muscles of extremities during convulsion, which precipitated by intravenous administration of metrazol (10% solution of Cardiazol) on cats. Needle electrodes (200 enamel insulated steel wire) were used as recording electrodes, and the spike wave (duration 20 to 60 msec. amplitude 50 to 100 μV by abovementioned electrode) was applicated as an indication of the excitement. 1) Motor cortex, caudate and pallidum, thalamus and black substance have demonstrated their important function in the propagating mechanism of the excitement. And motor cortex has been more sensitive than other structures. 2) On the occasion of metrazol convulsion, the spike wave is detected in the first place at cerebral cortex. The spiking at cerebral cortex propagates to basal ganglia with some seconds delay time, and then the spiking propagate also to basal ganglia. Moreover, the spiking at basal ganglia propagate to mid-brain nucleus. The onset of a convulsive movement is earlier than the beginning of the spiking at basal ganglia, and is delayed from the beginning of the spiking at cerebral cortex. The convulsive pattern of muscles change from former clonic convulsion to tonic convulsion in the course of propagation of the spiking to basal ganglia. 3) The auther has presumed that a typical epileptic convulsion, which has clonic-, tonic-and clonic stadium a its components, should have above mentioned propagating mechanism of the excitemnent from electroencephalographical findings.