This is the first longitudinal study to explore the effects of interactions among intrinsic capacity, social participation and family support on the trajectory of ADL in the older adults from the perspective of the life course. Social participation can effectively improve functional ability of older adults with low intrinsic capacity. Life care is beneficial for maintaining the functional ability of older adults with intact intrinsic capacity, but it accelerates the deterioration of the functional ability of older adults with low intrinsic capacity.