OBJECTIVES: The combined effects of physical activity and sleep duration on depressive symptoms trajectories, and age and gender disparities remain inadequately understood. The objective of this study was to identify the joint relationship of physical activity and sleep duration with depressive symptoms trajectories in Chinese middle-aged and older adults, and explored disparities in the joint associations. METHOD: This longitudinal analysis draws upon data from the China Health and Retirement Longitudinal Study. The analysis comprised 35063 observations. Linear mixed-effect models were employed to discern independent and joint correlation of physical activity and sleep duration with depressive symptoms trajectories. RESULTS: Chinese middle-aged and older adults showed increasing depressive symptoms trajectory. Physical activity and sleep duration interplayed to impact depressive symptoms trajectory in different ways. Compared to participants engaged in lower physical activity and short sleep, depressive symptom trajectories of those with higher physical activity and optimal sleep, and higher physical activity and short sleep increased less rapidly among group aged 60-70 years, as well as in women group. CONCLUSION: This study emphasized the importance of combining interventions targeting habits of physical activity and sleep for middle-aged and older adults to improve their mental health, especially for women and those aged 60-70 years.