Purpose: The purpose of this study was to identify the factors influencing ego-integrity and to investigate levels of ego-integrity, activities of daily living (ADL), instrumental activities of daily living (IADL), depression and their relationships in the institutionalized and non institutionalized elderly. Method: From July to August 2007，50 institutionalized elders and 47 non institutionalized elders were surveyed through structured questionnaires. Result: Ego-integrity of the institutionalized elders was significantly lower than the non-institutionalized elders (p=.001). ADL (p=.001), IADL (p=.001) and depression (p=.001) of the institutionalized elders was higher than the non-institutionalized elders ADL and IADL (p=.001), and ADL and depression (p=.023) had significant positive correlations in the institutionalized elders. Ego-integrity and depression (p=.008) had a significant negative correlation in the non institutionalized elders. ADL and IADL (p=.001), and ADL and depression (p=.002) had significant positive correlations in the non-institutionalized elders. In multiple linear regression analysis, institutionalization and depression were significantly related to ego integrity. Conclusion: It is necessary to try to enhance ego-integrity， ADL and IADL in the institutionalized elderly. Also, it is more urgent to develop health programs and a health care service system for institutionalized elders than for non-institutionalized elders, but also to develop supports to help elders stay in the community.