A social worker is a person who provides social service to people who are in needs. The job is becoming crucial in current society. A specialized aspect of the job can be achieved through practical education that can be built from more generalized foundation. However, the expertise of a social worker will be diminished when there is lack of sufficient practical education. Social worker supervision is a practical program that is designed to combine education and practice. Also a social worker often performs his or her job in the environment which lacks direct observation. This will not only deter the social worker\'s performance level but also rights of client. In order to prevent such problem, the constant teaching and watching over a worker are necessary. A medical social worker is a person who deals with ethical issues and lives of people in a very cohesive work environment. Therefore, the job requires even more professional and specialized skills and attitudes which can be provided through supervision. Until today, the studies of supervision has been only limited to social workers who are in social work organization. The studies has only been focused on function and style of supervision of Seoul and Kyung-Gi areas. The purpose of this study is to provide a foundation of supervision by understanding satisfaction and influences of supervision on medical social workers. The contents of the study are as follows: First, research on the actual condition of supervision of medical social workers. Second, research degree of supervision satisfaction of medical social workers. Third, research characteristics of supervision satisfaction. Fourth, find out the relationship between of supervision satisfaction and its characteristics. Fifth, compare the effects of different characteristics. Lastly, the supporting evidences of necessity of supervision of medical workers are presented below. The subject pool of the research include medical social workers of all regions of Korea. First, 67.4% of subjects were currently being supervised. 17.4% of the subjects were inofficially practicing supervisor roles. And rest of 15.2% of subjects were not even practicing any kinds of supervision. Second, the supervision satisfaction of medical social workers are found to be above average. Third, the average age of supervisees were 28 and mostly singles than married. The average period of experience of social workers were 5 years and 11 months. Of 5 years and 11months of worker\'s experience period, 4 years were experience as medical setting, mostly working as handling personal matters of clients. 38.9% of the medical social workers work in university hospitals. The workers have independent department of social work and personalized offices. Average weekly working hours of the supervisees are approximately 48 hours. Most of the workers are satisfied with work amount and hours. Among them, 43% pointed out about the work overload in given working hours. Average age of supervisors were 38 years old and married than singles. 59.3% of them are in graduate schools including people getting master\'s degrees and 31.4% are in doctoral programs. Most of the supervisors have high level of education. Overall experience of supervisors were 12.5 years, of 11.9 years as medical workers which is 7 years different from supervisees. Looking at the structure of supervision, only 38% of workers who are handling case studies receive regular supervision. The workers were experiencing positive attitudes about being supervised in dimensions of authority, knowledge, and evaluation. On the other hand, the workers experienced negative attitudes regarding matters such as practice sharing and anger confrontation The correlation between supervision satisfaction and various factors are observed. These factors include education of supervisee, main tasks, ricense of mental health social worker, exsistence of personalized work space, number of employees, main parts and case charge of supervisors, content and role and supervision, authority, knowledge, evaluation, and sharing of practices. Fifth, the influences of supervision satisfaction include followings; characteristics of experience of supervision, general characteristics of supervisees, characteristic of supervision structure and characteristic of work environment. Some of theses influnences may contain some variables including, main tasks of supervisees, license of mental health social worker, presence of absence of having personalized work space, and experience of sharing of practices. Through hierarchical multiple regression, it is found that experience of evaluation, authority, and sharing of practices are the major components of that affect supervision satisfaction among other variables. As a conclusion, the practice of medical social work supervision needs to be provided to all the medical social workers. It is necessary to increase supervision satisfaction. It is also important to give specific direction of proper supervision and to raise awareness of fair evaluation, use of authority, and importance of sharing of practices.