Abstract: 217 old people, from three communities of Beijing, participated the study of the aging of primary mental ability. They were required to complete five cognitive tests, namely inductive reasoning, number computing, mental rotation, verbal meaning, and word fluency. Also working memory, processing speed and sensory function were examined for all subjects. Results indicated that age and educational level could influence the cognitive function independently. Educational level was an important and widespread supportive factor for old adults’ cognition. Working memory and processing speed were the mediating variables for the positive effects of educational level on cognitive function.

Key words: cognitive aging, educational level, primary mental abilities