n the patients with epilepsy, especially in psychomotor epilepsy the epileptiform discharges occasionally has its origin from the basal structure of brain or the mesial side of temporal lobe which is not accessible to the standard surface EEG. The nasopharyngeal electrode, which was introduced by Grinker and Serota in 1938 and modified several times, is a kind of special electrodes to investigate electrical activity from the mesiobasal part of the temporal lobe, and there are several studies about clincial usefulness of the nesopharyngeal EEGs with some controversies in other countries. In this country, however, there is no reports about this topic, and in fact only a few laboratories are known to use the nasopharyngeal electrode. To determine clinical significance of nasapharyngeal EEG in patients with psychomotor seizure, the selecting records of 123 cases who had been taken both standard surface and nasopharyngeal EEG are analysed and compared with each other. Eight nine of cases are the patients with seizure disorder including 13 simple partial seizure with or without secondary generalization, 47 psychomotor seizure (or complex partial seizure) with or without secondary generalization and 29 primary generalized seizure, diagnosed by history and clincial findings. The other 34 cases are the patients with similar symptoms of psychomotor seizure but without definite convulsion. The standard surface EEG revealed 48 (56%) of epileptiform activity, 24(28%) of nonspecific dysrrhytmia and 17(19%) of normal record in 89 patients with seizure discharges. There are 38 patients who showed spike or sharp wave on nasopharyngeal generalized seizures. In nonseizure cases, however, epileptiform activity is not detected on nasopharyngeal electrodes. Five cases are technically unsatisfactory. The significances of nasopharyngeal EEG in 38 with epiletiform discharges on nasopharyngeal electrode(s) are; more definite and prominent epileptiform activity in 17 and unexpected nasopharyngeal discharges in 10 patients including 5 with normal standard surface EEGs. In 47 psychomotor seizure, 42 cases (89%) reveal epileptiform discharges on standard surface and/or nasopharyngeal EEG and the sensitivity of nasopharyngeal EEG (75%) is higher than that of standard surface.