Abstract: Objective To investigate the prevalence of mild cognitive impairment(MCI) and its related factors among elderly people in communities of Ningbo city.Methods From September to December 2009,we carried out a random cluster sampling survey to investigate the elderly aged 60 years or above living in six communities of Ningbo city.The survey was conducted in two stages.In the first stage,an interviewto the subjects was performed by trained interviewers for a general questionnaire survey and Mini Mental State Examination(MMSE).In the second stage,for the subjects with distinct cognitive impairment or dysmnesia and those with the scores less than the cut-off point of MMSE,the tests including physical examination,Global Deterioration Scale,Hachinski Ischemic Scale,Hamilton Depression Scale,Clinical Dementia Rating,and neurological examination were conducted.Then MCI was diagnosed by the consensus of two psychiatrists.The data were analyzed with SPSS 15.0.Results A total of 1 227 subjects(536 males and 691 females) were surveyed.Among the subjects,131(10.68%) were diagnosed with MCI.The prevalences of MCI were significantly different among the subjects of different age,education,and occupation(P < 0.05 for all).Conclusion Older age,loweducation,smoking,alcohol consumption,less intake of fish and seafood,living alone,and lack of reading may increase the incidence of MCI among the elderly.