The final destination of the mental health care is to make the patient recover his productive social skill, forcusing on his social rehabilitation, with the basic goal of avoiding unnecessary hospitalized treatment and removing of the symptom. It also aims to strengthen the community-based mental treatment, avoiding hospitalized treatment as much as possible, thus balancing and connecting the two strategies. For hospitalized treatment should be practised only in necessary cases and partial hospitalization should be activated. As for hospitalization facilities, they should be restricted in size suitable for the treatment of patient. Mental Health Law is the nation`s effort to provide best treatment for the patients who cannot make effort to enhance the quality of life which proper treatment for himself. In this task Psychiatric-Mental Health Nurse Practitioner(PMHNP) plays an important role, together with mental illness specialist, in prevention and treatment of mental illness, mental health consulting as well as social rehabilitation of the patient. In this sense the role of PMHNP as a highly specialized personnel, must not be underestimated. In this study, the researcher tries to suggest how to widen the role of PMHNP and how to prepare for that. To approach the goal of this research, this thesis studies closely the role of the nurse, diving it into three-1) role in general, 2) role in particular in each section, 3) role as a case manger-and suggests its orientation. It also suggests the nursing management of chronic mental illness patient and the estimation and tasks of mental health nursing. The suggestions about the impending tasks of community-based mental health care in this thesis are hoped to contribute to settling the activity of PMHNP who is inevitable for the mental health of the community people.