Abstract: From the perspective of spatiotemporal sociology, this paper examines the current problem of physical activity promotion in Chinese children and adolescents. It is concluded that school, family, and community fields where physical activity takes place have the characteristics of clear physical education curriculum time arrangement, overlap of intergenerational interaction, and accelerated spatial remodeling of built environment. Time famine caused by biased values, spatial differentiation caused by unbalanced development, extension of time and space caused by digital wave, and compression of time and space exacerbated by intensification trend are the spatiotemporal hidden worries behind the decline of physical activity. Based on this, the solutions and adaptation approaches are put forward: to improve the overall governance efficiency through the power spatiotemporal adjustment, to promote the intelligent development through the information spatiotemporal adjustment, to establish the interpersonal support community through the relationship spatiotemporal adjustment, to enhance the individual drive through the psychology spatiotemporal adjustment, and to cultivate the active health behavior pattern through the life spatiotemporal adjustment.

Key words: children and adolescents, physical activity promotion, spatiotemporal sociology, physical fitness