The purpose of this study was to extend our knowledge about how social support and family functioning affect mental health, and to examine the buffering effects of support in the presence of health stressors. A random cluster sample of 507 elderly community people were surveyed with a structured questionnaire, which included the depression and anxiety subscale of the Chinese version of Symptom Checklist 90-R (SCL-90-R), Social Support Rating Scale (SSRS), Family Emotional Involvement and Criticism Scale (FEICS), Short Portable Mental Status Questionnaire (SPMSQ), and the Katz Activities of Daily Living Scale (KADL). Results revealed that women had more anxiety symptoms than men (mean=3.49; 95% CI: 3.02-3.95 versus mean=2.56; 95% CI: 2.27-2.85). Emotional support was more important than instrumental support for psychological symptoms. Family emotional involvement was inversely correlated to depression (r=-0.19) and anxiety (r=-0.22), while criticism was positively correlated to depression (r=0.29) and anxiety (r=0.31). Multivariate analysis revealed that women, impaired cognitive function, urban residents with chronic diseases, less emotional support, and more criticism from the family were associated with more depressive and anxiety symptoms. Family involvement had buffering effects on psychological symptoms for people with cognitive impairment and medical diseases. Our results imply that elderly people with mental symptoms and chronic medical diseases benefit more from family involvement.