Purpose: The purpose of this study was to identify factors influencing the outcome of psychosocial rehabilitation for persons with chronic mental illness and to suggest a hypothetical model of psychosocial rehabilitation which is based on the relationship between influencing factors and then to test its fitness empirically. Method: Data was collected from persons with a chronic mental illness using a self-report questionnaire, and from their case managers using an observed rating questionnaire. A total of 220 cases were used in the final analysis, and a hypothetical model was verified through covariance structure analysis using LISREL. Result: 1) The fitness indices of the model were $X^2=133.77$ (df=48, p=.00), GFI=0.93, AGFI=0.87, RMR=2.32, NNFI=0.95 and NFI=0.95. Twelve paths among fifteen proved to be significant. 2) Psychosocial rehabilitation was influenced directly by symptoms, daily living skill and self-concept, and was influenced indirectly by the psychosocial rehabilitation program service. Psychosocial rehabilitation accounted for 32% of variance of these factors. Conclusion: This study is expected to contribute to understanding the psychosocial rehabilitation phenomena. Besides it will provide basic information for developing strategies of bio-psycho-sociological interventions and evaluations in regard to influential factors of psychosocial rehabilitation.