Despite the intensive family Planning program of the government, which has reduced the :average population growth to 2.0 percent in 1970, the continuing high fertility rates and poor family planning services in urban slum areas has been continually pointed out by various evaluation seminars. Thus, it was felt that a study of the current status of family planning in an urban slum population was needed. The aims of the study were to: (1) delineate the general characteristics of the urban slum population (2) discover the knowledge, attitudes, and practice of family planing. (3) determine what was felt to be the ideal number of children. (4) determine the status of induced abortion. A random stratified sample of 200 women was selected from a population of 3, 118 married women, 20-49 years of age, living in the Yonsei Community Health Project area and registered at the Yonhee Community Health Service Institute. The respondents were interviewed by the investigates, using a pretested questionary, from the period of October 1 to October 30, 1972. The findings of the Study were as follows: 1. Afore than half of the respondents were in the high fertility age group (25-34): of lower educational level (under primary School) : from rural areas: and with unstable sources of income. 2. The average respondent had 3.6 living children. 3. Most of the respondents had knowledge of contraceptive methods such as the Loop(78, 5%) and Oral pill (87.0%). 4. Seventy seven percent of the respondents recognized the Health Center as an available source for family planning. 5. About seventy percent of the respondents approved of family planning. 6. Eighty four point five percent of all the respondents answered that using contraceptives is harmful to maternal health. 7. Currently, 21.0 percent of the respondents were using contraceptives, while 40.0 percent of the respondents were current users or had used contraceptives. 5. Of the respondents who had ever stopped using contraceptives, 78.0 percent gave side effects as the reason they discontinued the method. 9. The average number of ideal children reported by the respondents was 3.5. 10. If they had only 2 daughters, 85.5 Percent of the respondents thought they must have more children. 11. Sixty nine point five percent of the respondents approved of induced abortion for unwanted pregnancies, while 34.5 percent of the respondents had experienced induced abortion for unwanted pregnancies. The mean number of induced abortion for unwanted pregnancies was 0.7. 12. The result of this study showed that such urban slum population would be one of the most important target of the family planning services, therefore further social-psychological researches with technical development on this area are recommended.