Purpose: The purpose of the present study is to examine the effects on preventive care program for cognitive function decline among community-dwelling frail elderly people. Methods: Subjects were 16 frail elderly people, included seven male and nine female, and whose mean age was 79.6 (SD7.5). The care program consisting of activities stimulate their cognitive function for two hours, four times during two months. We measured GDS (Geriatric Depression Scale) as depression, MMSE (Mini-Mental State Examination) and Stroop Color-Word Test as cognitive function at the time of pre-intervention and post-intervention. Results: Scores of GDS have decreased, although the change is not significant. Scores of MMSE significantly improved (p=0.002) at the point of post-intervention. Orientation, subscale of MMSE, significantly improved (p=0.03). Regarding Stroop Color-Word Test, three subjects who could not complete the task at the point of pre-intervention could complete it at the point of post-intervention with few mistakes. Scores of MMSE were improved significantly among male subjects (p=0.03) and younger subjects (p=0.03). Discussion and Conclusion: The results suggest that the present preventive care program was effective to improve cognitive functions among community-dwelling frail elderly people. Future research should be conducted, expanding numbers of subjects, examining the effect on gender or age difference.