Background: Lower educational attainment is associated with lower cognitive performance and a higher risk of dementia in older adults. However, the extent to which other socioeconomic markers might contribute to age-related mental decline and if these influences differ between Western and Eastern countries is less understood.Objectives: We carried out a coordinated analysis of the associations between individual and area-level socioeconomic markers (e.g., education, household wealth, urbanicity) with memory performance and memory decline over up to 8 years of follow up in England and China.Methods: The two analytical samples included 6,768 participants aged 50+ from the English Longitudinal Study of Aging (ELSA) and 10,253 participants aged 50+ from the Chinese Health and Retirement Longitudinal Study (CHARLS). Mixed linear models were employed to examine the association between baseline socioeconomic markers and change in memory over up to 8 years of the follow-up period, including five measurement occasions in ELSA and four measurement occasions in CHARLS. Models were adjusted for age, sex, marital status, hypertension, heart problems, diabetes, depressive symptoms, alcohol, and smoking.Results: Our analyses showed that higher education and wealth were associated with better baseline memory in both England and China, but the impact of area-based characteristics such as urbanicity differed between the two countries. For English individuals, living in a rural area was indicative of a slight advantage in baseline memory when compared with those living in the urban area, while for the Chinese counterparts, the opposite pattern was observed. The rates of memory decline also appeared to be socioeconomically patterned, primarily by higher education and wealth in the Chinese population and urbanicity in both England and China.Conclusions: Our findings suggest a substantial impact of socioeconomic inequalities on baseline memory performance at both individual and area-level characteristics in both cohorts and a pronounced effect of education and urbanicity on memory decline in China. Public health strategies for preventing cognitive decline and dementia should target the socioeconomic gaps at individual, meso, micro and macro levels to reduce health disparities and protect those particularly disadvantaged in England and China.Funding: None to declare. Declaration of Interest: None to declare. Ethical Approval: Ethical approval for each one of the ELSA waves was granted from the National Research Ethics Service (London Multicentre Research Ethics Committee [MREC/01/2/91]. All participants provided informed consent