Objective To determine the effect of aerobic exercise(brisk walking) on cognitive function, abilities in daily life, and psychological symptoms in the patients with mild to moderate A1zheimer’s disease (AD). Methods A total of 78 patients with mild to moderate AD admitted to our hospital from June 2013 to December 2014 were recruited in this study. They were randomly divided into control group(conventional therapy, n＝39) and exercise group(conventional therapy＋outdoor brisk walking, n＝39). Barthel index (BI), Mini- Mental State Examination(MMSE) and Neuropsychiatric Inventory (NPI) were used to evaluate the efficacy of the two groups before and 16 weeks after treatment. Results Before treatment, the BI, MMSE scores and NPI scores had no significant difference between two groups. After 16 weeks’ brisk walking, the patients of the exercise group had significantly higher BI and MMSE scores and obviously lower NPI scores when compared with the control group(P＜0.05). Conclusion Aerobic exercise(brisk walking) improves the memory and abilities in daily life, and relieves the psychological symptoms in the patients with mild to moderate AD.