Abstract This study investigated the relationship between coresidence and the well-being of adult child caregivers and examined the domain-specific caregiver burden as the cognitive appraisal pathway in such a relationship in the context of urban China. Data on adult child caregivers (N = 334) came from a regionally representative study using the Family Caregivers for the Frail and Very Elderly survey in 2010, in Shanghai, China. Multistage random sampling was used to collect data. The 24-item Chinese version of the Caregiver Burden Inventory was used to assess five domains of caregiver burden: time dependence, developmental, physical, social, and emotional. Well-being outcomes included depressive symptoms and self-rated health. Path analyses were used to estimate direct and indirect effects on caregiver well-being outcomes. Social burden was found to mediate the relationship between coresidence and caregiver well-being outcomes. Through the intermediary pathway of domain-specific cognitive appraisal, particularly caregiver social burden, coresidence with the care recipient exerts negative influences on caregiver well-being. Healthcare professionals, such as social workers providing support and services to caregivers, should understand the importance of assessing domain-specific burden and incorporate tailored intervention strategies to prevent or reduce social burden, especially among coresident adult child caregivers.