ObjectivesTo estimate the prevalence of mild cognitive impairment (MCI) in Beijing, China, and to explore the potential protective and risk factors for MCI. DesignPopulation-based survey. SettingThe Beijing Ageing Brain Rejuvenation Initiative (BABRI). ParticipantsParticipants randomly recruited from BABRI (N=1,211). MeasurementsParticipants underwent a battery of neuropsychological examinations to determine cognitive function and answered a series of personal questions. The prevalence of MCI and its subtypes were computed using Petersen's criteria. Influencing factors for MCI were estimated based on participant medical history, lifestyle, diet, and leisure activities. ResultsOne thousand twenty (aged >55, mean 63.96.6; 36.7% male) subjects completed the neuropsychological tests. The overall prevalence of MCI was 15.7%, with single-domain amnestic, multiple-domain amnestic, and nonamnestic subtype prevalences of 6.4%, 3.7%, and 5.6%, respectively. Eight hundred sixty-four subjects were used for the case-control analysis. Hypertension, diabetes mellitus, and cerebrovascular disease were found to be associated with MCI. Healthy diet and greater involvement in physical, intellectual, and social activities were associated with a lower risk of MCI. ConclusionThe prevalence of MCI was compatible with that found in previous published reports, and the information on the epidemiology of MCI, especially risk factors, may help to explore therapeutic strategies and preventive approaches to delay conversion to dementia.