<p>Community regeneration has become a critical topic in contemporary urban studies and is a key approach to enhancing the quality of the human settlement. Meanwhile, participatory planning is the implementation path to successful community regeneration. This study addresses the long-neglected challenges of participatory planning in China's community regeneration and proposes a more systematic research framework. Grounded in the functionalist perspective of the Chicago School, this research primarily employs a literature review, comparison of planning documents, professional opinions, and empirical analysis. Focusing on community planning practices in China, this study constructs a theoretical model of "function–structure–relation–system" to reinterpret the spatial boundaries and influencing factors of regeneration units from the perspectives of regulation conduction, function control, and index control. This paper argues that community regeneration can be effectively enhanced through a functionalist approach, utilizing bottom-up participatory planning that incorporates feedback from residents to refine interventions. It emphasizes the importance of improving functional coordination among stakeholders and sectors. This paper advocates for the readjustment of the planning system to integrate detailed regulatory planning, management units, regeneration units, and community planning. This integration should connect the city's master plan to specific site construction layouts and involve the restructuring of community sizes and boundaries as spatial functional units for planning. By treating a community as a functional system, planners can bridge the gap between functionalist theory and practical planning tools. It contributes to theoretical advancements in community regeneration, provides speculative insights into co-creation practices, enriches the theoretical connotation of community regeneration.</p>