This paper illustrate residual hearing and socio-medical background on the hearing impaired children, 207 coming to Deaf School, attached to Hankuk Social Work College, Tague, Korea. The survey was performed through interview with their parents and testing by diagnostic audiometer (TRIO, AS 105 type) at soundproof room from March 10, to November 28, 1973. The results obtained were as follows. 1) The attendance rate of the compulsory primary school was markedly lower tendency in female than according to directly proprotinoal to prevalence rate of deafness amont them, If was showed the deeper gap in the more superior school (middle and high school). 2) Who entered at the suitable age to each school (six years old to primary school, 12 years to middle and 15 years to high) was 11.3%. And who were enrolled in school age to each school (6-11) years for primary. 12-14 years for middle and 15-17 years for high) was 45.9% (43.7% in male, 50.0% in female). 3)As causative disease, congenital case, were 23.6% include of 13.5% of heredity and 10.1% of troubles during pregnancy ; the total acquired cases were 47.9%, it was classified as 11.6% of convulsion from any other diseases, 7.7% of measles, 7.7% of other febrile diseases, 3.4% of drug (the most of streptomycin) intoxication, 2.4% of meningitls, 1.5% of epidemic encephalitis and 31.3% of other diseases ; and unknown cases were 28.5%. 4)31.4% of who included congenital cases lost their hearing within six months old, 11.6% in 6-11 months. 9.7% n 1-2 years old and 14.0% in 2-3years old. Consequently we obtained that the most cases 90.0% were lost their hearing within 3 years after birth.