The purpose of this study is to evaluate the cognitive functional improvement of cognitive occupational therapy using cognitive function, activities of daily living (ADL) executive function and depression tests in community living elders with mild cognitive impairment (MCI) and dementia. Thirty two elders who diagnosed MCI (n=13) and dementia (n=19) were enrolled in this study. They visited to local elder welfare office and nursing care home from Feb. 2012 to Jun. 2012. They received occupational activity program in terms of physical activity, cognitive function and occupational function of Craft as the manner of a session per week for 8 weeks. The cognitive function, executive function, depression score were improved in both group. Furthermore in MCI participants, cognitive function scores for concentration and memory functions were significant improved more than dementia subjects. Further studies dealing with the development of novel occupational program for cognitive function improvement and its preventive effects were needed.