This study was performed to investigate the effects of aluminum sulfate administration on the brain tissues of old rats, when given at different concentrations. The experiment attempted to further ascertain whether aluminum exposure cause Alzheimer's disease. Seventy-five aged Sprague-Dawley rats were divided into five groups; a control group, 2 ppm aluminum sulfate group, 20 ppm aluminum sulfate group, 40 ppm aluminum sulfate group, and 200 ppm aluminum sulfate group, and were kept on the respective diets for 12 weeks. In order to understand the influence of aluminum on the brain, serum aluminum concentrations, phospholipid composition, and catecholamine concentrations were compared between the aluminum-treated groups and the normal group. According to the results, serum aluminum was higher in the aluminum sulfate-treated groups than in the normal group. Within the cortex, catecholamine concentrationes were significantly increased but cerebellum and brainstem tissue were significantly decreased, in the aluminum sulfate-treated groups compared to the normal group. For phospholipid composition, phosphatidyl inositol was significantly increased wherase phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl serine were significantly decreased in the aluminum sulfate-treated groups versus the normal group. Based on the data, increased aluminum consumption in experimental animals causes increased serum aluminum levels and catecholamine variation. These phenomena are very similar to conditions of Alzherimer's disease. Therfore, the results of this experiment further suggest that aluminum cause Alzherimer's disease, coinciding with reports that aluminum is a cause of neurofibrilly tangles in the brain.