Abstract: Objective This research aims to, from the perspective of children's geographies, explore changes in children's outdoor play experience across the three generations of contemporary children and their parents and grandparents.Methods Taking Shichahai Area in Beijing as an example, this research, by mixed data collection methods of semi-structured interview, behavior observation and questionnaire, records and compares children's outdoor play experience in different generations from the dimensions of outdoor play space, playmate, activity and time based on SPAT model.Results The research findings show that, the range of children's daily outdoor activities keeps narrowing; children's outdoor playmates become increasingly homogeneous; there are fewer and fewer types of outdoor plays for children; and the time spent by children outdoors becomes shorter and shorter.Conclusion The main reasons for intergenerational changes lie in the rapid change of urban built environment during the process of urbanization, especially the sharp reduction of outdoor public activity spaces, which leaves children with very limited space for outdoor activities. Additionally, in terms of urban social environment, population mobility has altered the social atmosphere of traditional communities, significantly and negatively impacting the ways in which children engage in outdoor activities. This research may provide theoretical basis for improving children's outdoor play experience.