Accepting the health as the fundamental human right, the nation and society came to admit the duty to give it to all the people. Korean government is expanding the Primary Health Care as one of the policies for developing the people's health by the lead of community. Like this current situation the School Health Service which is the center of community Health Service schould be active to keep, promote and maintain the health of students and teachers. This investigation was attempted to help to establish the basis of the Health Education Program which would perform the health education efficiently and bring the reforming of student's health control, by measuring the degree of junior high school student's practice concerning health care and con-firming the relationship of knowledge, concern and level of health. The subjects for this study were made up 296 boys at the third grade in a school, located in Seoul. The tool for this study was questionaire. Data were collected for five days, September 22∼26, 1983. The investigators explained the students how to answer the questions of the survey questionaire and then collected the survey cards immediately. The data were analyzed by means of percentages, Pearson Correlation Coefficient and Stepwise Multiple Regression. The results of this study are as follows. 1. The subjects' reaction to the practice concerning Health Care; According to the average proportion of practice concerning health care, subjects' practice in the aspect of Infectious Disease Care is the highest 82.4％ and they showed their practice in the aspect of the accident prevention by 77.5% and in the aspect of mental health by 74.8%. Their practice in the aspect of personal hygiene and daily lifehabit is the lowest 71.2%. 2. Health Knowledge; The whole mark distribution of health knowledge is ranged from the lowest 4 point to the highest, 30 point, therefore point range is 26.0. The Average point is 16.58. 11.2% of students solved more than two thirds of personal knowledge levels. 81.4% of students did more than one third of them. 7.415 of students did less than one third of them. 3. Health Concern; The Students of the average 3.99 point respond positively to the question about the health concern, ‘They think health is more important than money’, this is the highest rate. The students of the average 2.78 respond“when they are sick, they enter the appointed hospital where they own choose”, while it is the lowest. 4. Subjects' response to the health level are at follow: Very healthy 26.0%, healthy 47.0%, less healthy 10.5%, 34.9% of them have ever been sick within two weeks, the number of symptoms they reported amount to 114 and the number of cases poi one person is 0.35. 5. The hypotheses test about the practice concerning health care and the factor which effect on it. 1) The main first hypothesis:“The more knowledge of health the subjects have, the better they practice health care.”was accepted. (r=0.1582, p <0.05) 2) The minor first hypothesis:“The more interest in health subjects have, the better they practice”was accepted. (r=0.4354, p ＜0.001) 3) The minor second hypothesis;“The healthier subjects are, the better they practice health care”was accepted. (r=0.1069, p＜0.05) As other test, partical correlation test is performed in other refine whether health knowledge, a fact influencing the students practice concerning health care, is associated with the practice after controlling the third variables. First, after controlling health concern, the correlation of health knowledge and practice concerning health care was kept. (r=0.1347, p <0.005) Second, after controlling health level, the correlation of health knowledge and practice concerning health care was kept. (r=0.1526, p <0.005) And finally, after controlling economic state, the correlation of health knowledge and practice concern-ing health care was kept. (r=0.1413, p <0.05) Additionally Stepwise Multiple Regression between practice concerning health care and variables. 1.6591 of compliance was explained with the know-ledge (F=5.584, p <0.05), 20.0% of compliance was explained with the health concern added to knowledge. (F=63,213, p <0.005) As the above, health knowledge obviously have effects on the practice about the health care. But, contrary to researcher's expectation, health concern has more affects than health knowledge. Therefore, we must grope the plan to enhance health concern through the regular curriculum and systematic health education for students. Besides, we must study further on, to find the factors which have affect on the practice concerning health care.