Background: In China, improving mental health has been far behind its accomplishments for other diseases. With depression as one of the most prevalent mental disorders, the aim of this study was to evaluate temporal trends in the prevalence and treatment of those who screen positive for depression in China, by age, gender, and province. Methods: We used data from three nationally representative sample surveys: the China Health and Retirement Longitudinal Study (CHARLS), the China Family Panel Studies (CFPS), and the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Depression was judged by the Centre for Epidemiologic Studies Depression Scale. Access to treatment was judged by two items: if respondents received any treatment like anti-depressants, or if respondents received counselling from a mental health professional. Survey-specific weighted regressions were fitted to estimate the temporal trend and subgroup disparities, and then pooled by meta-analysis. Results: In total 168,887 respondents were investigated. The overall prevalence of China populations who screen positive for depression was 25.7% (95% CI 25.2–26.2) during 2016–2018, decreased from 32.2% (95% CI 31.6–32.8) during 2011–2012. The gender gap increased with age and had no significant improvement from 2011–2012 to 2016–2018. The prevalence of depression in developed areas is more likely to show a lower value and decreasing trend, while the prevalence in underdeveloped areas is more likely to show a higher value and increasing trend, from 2011–2012 to 2016–2018. The overall proportion of those who received any needed treatment or counselling from a mental health professional slightly increased from 2011 (0.5%, 95% CI 0.4–0.7) to 2018 (0.9%, 95% CI 0.7–1.2), and mainly occurred for older adults aged 75 and above. Conclusion: The prevalence of those who screen positive for depression decreased by about 6.5% from 2011–2012 to 2016–2018 in China, but only tiny improvements were made in accessibility to mental health care. Corresponding disparities were identified in age, gender, and province.