To investigate the factors which affecting the cognitive impairment of the 60 or more age group, the authors surveyed for the subjects in some area of Kyungnam Province. 201 studied subjects were tested for cognitive function with mini-mental state examination(MMSE). Information on demographic characteristics and life style has been collected through direct interview. The concentration of Al and Ca of subject's drinking water, which might be related with cognition, was measured by Inductively Coupled Argon Plasma Spectrometer. The main results were summarized as follows. 1. The prevalence rate of cognitive impairment was 18.4% in male and 45.2% in female and this sexual difference was statistically significant(p=0.03). And the uneducated or illiterated showed significantly high prevalence rate of cognitive impairment(p=0.02). 2. In stratified analysis by sex and education year, we can not see significant trend indicating the neurotoxic effects of aluminum and protective effects of calcium to the cognitive function(p>0.05). 3. The correlation between the concentration of aluminum in drinking water and the MMSE score in whole subjects showed weak negative relationship(r=-0.066). But there was no statistical significance(p=0.434).