This survey was conducted by a questionnaire method on out-patients and in-patients, both below 15 years of age, having. been treated during the past year (1961.4-1962.3) at 15 neuropsychiatric institutions in Miyagi Prefecture and at 198 instituions (selected out of 619 institutions) in Japan. The results were as follows. 1) In Miyagi prefecture, responses were obtained from all institutions surveyed. Informations on 800 cases of out-patients and 79 cases of in-patients were obtained. The rate of incidence of these patients among the corresponding age group of the prefecture was 0.15 percent. The order of the number of these patients by age group was a follows: primary schools age group>junior high schools age group>pre-schools age group. 2) In the whole country, on the other hand, we received 69 answers out of 198 (34.3%) and descriptions on 5122 out-patients and 409 in-patients were obtained. The rate of incidence of these patients among corresponding total population and the number of patients by age group showed generally the same tendency as found in Miyagi Prefecture. 3) The order of the incidence according to disorders was as follows in Miyagi Prefecture, epilepsy) others>brain organic disease>oligophrenia> schizophrenia>psycho-neurosis; in the whole country, epilepsy>oligophrenia>others>psycho neurosis>brain organic disease>schizophrenia. Epilepsy accounted for about 50 percent of all patients, but the incidence of the so called behavior problem child was comparatively small.