Backgrounds: This research was undertaken to determine the effect of social support for chronic mental patients on their self-care capacity and to provide basic data for the development of health promotion programs for them. Methods/Statistical Analysis: The subjects of this research were 302 chronic mental patients who were hospitalised in a national hospital in Seoul and they signed on the informed agreement document. The tools used were Multi-dimensional Scale of Perceived Social Support Scale(MSPSS) of Gregory and others, revised by Yang and Mental Health Self-Care Capacity Tool (MH-SCA) of West and Isenberg revised by Her. Real number, percentage, t-test, ANOVA, Pearson's Correlation, and hierarchical multiple regression analysis was analysed using SPSS program. Results: A significant correlation was found among self-care capacity and social support (family members (r =.345, p<.001), friends (r =.382, p<.001), and medical staff (r =.426, p<.001)) for chronic mental patients. Previous researches showed that supports from family, friends, and medical staff had positive influence on self-care capacity and also this study shows similar results (Adj R 2 =.229, F = 30.842, p<.001). It was found that the higher social support for chronic mental patients increased, the higher self-care capacity increased. Since chronic mental patients are separated from their families during hospitalisation, enhancing support of medical staff and friends as well as family members can be one of the methods to increase self-care capacity. Conclusion: To enhance the self-care capacity of chronic mental patients, various social supporting systems should be established to help them live an independent life along with the support from family members and medical staff.