Abstract: Objective:To analyze the effects of different doses of donepezil combined with olanzapine on cognitive function and mental symptoms of patients with Alzheimer's disease(AD),and provide the guidance in clinical medication.Methods:Ninety-five patients with AD from January 2010 to December 2015 were divided into the observation group and control group according to the random number table method.The observation group and control group were treated with olanzapine combined with 10 mg/d and 5 mg/d donepezil by oral for 6 months,respectively.Results:The differences of the scores of NPI and MMS,and degree of care distress between two groups before treatment were not statistically significant(P>0.05).After 6 months of treatment,the scores of NPI and MMSE,and degree of care distress in observation group were better than those in control group(P<0.01),and which after treatment was significantly better than that before treatment in two groups(P<0.01).The scores of high emotion,apathy,hallucination,delusion,irritability and uncontrollable behavior in observation group were significantly better than those in control group(P<0.01).Conclusions:The 10 mg/d donepezil combined with olanzapine can effectively improve the psychiatric symptoms and cognitive function of patients with AD.