摘要： Objective：To explore the changes of clinical features and rest-state functional MRI（fMRI） changes of olfactory dysfunction in patients with Alzheimer’s disease（ AD）. Methods：Total 31 AD patients were consecutively recruited from the Department of Geriatrics，Beijing Tiantan Hospital，Capital Medical University from April 2016 to November 2016. Argentina Hyposmia Rating Scale（ AHRS）were used for screening olfaction. Olfactory function test was tested with Sniffi n’ Sticks which consisted of three tests：odor threshold （THR），odor discrimination （DIS），odor identification （ID） and TDI score were obtained by summing up the score of THR，DIS and ID. AD patients were divided into olfactory dysfunction （AD-OD） group and non-olfactory dysfunction （AD-NOD） group according to the hyposmia standard adjusted for age and gender in Sniffi n’ Sticks test. Demographic information of participants was recorded. Cognitive abilities were evaluated by a series of neuropsychological scales. The fMRI based on blood oxygen level dependent（ BOLD） was performed at resting state；the differences of amplitude of low frequency fl uctuation（ ALFF） and regional homogeneity（ ReHo） were statistically analyzed. Results：①Of 31 AD patients，there were 14 cases（45.1%） in AD patients with olfactory disorder（ AD-OD） group and 17 （54.8%） cases in AD patients without olfactory disorder（ AD-NOD） group. There were 10 cases（ 32.2%）were self-reported olfactory dysfunction. The median TDI score was （22.38±7.72） in AD patients，with median THR score（ 4.55±2.31），median DIS（ 8.97±3.07） score and median ID score（ 8.86±3.69）. In AD-OD group，the scores of TDI，THR，DIS and ID were all signifi cantly lower than in AD-NOD group（P<0.05）. ②The median AHRS score is（ 21.81±2.44） in AD patients. AHRS score of AD-OD group is signifi cantly lower than in AD-NOD group（ P<0.05）. ③There is a large positive correlation between AHRS score and TDI score（ r=0.648，P<0.001）. ④There is no difference between AD-OD group and ADNOD group in gender，age，smoking prevalence，disease duration and education levels （P>0.05）. ⑤In neurological tests of mini-mental status examination （MMSE），Montreal Cognitive Assessment （MoCA），auditory verbal memory test（ AVMT），Rey-Osterreich complex fi gure test and Neuropsychiatric Inventory Questionnaire（ NPI） and Stroop color-word test（ CWT），the AD-OD group were all significantly lower than AD-NOD group（ P<0.05） . The scores of TDI were positively correlated with the scores of the scores of MMSE，MoCA，AVMT，Rey-Osterreich complex figure test and CWT（r>0，P<0.05）. ⑥Compared to AD-NOD group，AD-OD patients exhibited increased ALFF values in both superior temporal gyrus，left limbic lobe and cingulate gyrus. AD-OD patients also exhibited increased ReHo values in right superior temporal gyrus. Conclusion：There is a high incidence of olfactory dysfunction in AD patients， so olfactory dysfunction may be a potential early warning sign for AD. The olfactory dysfunction in AD mainly manifests as decline of odor discrimination and odor identifi cation and odor threshold. AHRS can be used for olfaction screening in AD patients. AD patients with olfactory dysfunction have more serious damages in different cognitive domains. Olfactory dysfunction may contribute to the changes of restingstate function of AD patients. AD patients with olfactory dysfunction may have function inhibition in both superior temporal gyrus，left limbic lobe and cingulate gyrus，which may provide new method or idea for the early recognition and exploring the mechanism of AD.