Objective: To investigate the effect of socioeconomic status on the prevalence of senile dementia in China. Methods: Cluster sampling method was used to choose 7 072 elderly residents (≥60 years old) from six provinces (cities) in China, and “10/66” algorithm in international dementia project was used to screen the positive cases in household survey. Results: A total of 360 elderly people were diagnosed as dementia. The prevalence rate of dementia was 5.1%. Among socioeconomic status’ factors, single, low education and low income were risk factors for senile dementia. Conclusion: For the senile dementia, the risk of people who had high socioeconomic status is lower than the people who had low socioeconomic status.