Currently, many industrial cities in Northeast China are grappling with a surge in brownfields, population loss, and environmental degradation, largely driven by industrial decline. Consequently, brownfield regeneration has emerged as a critical pathway for exploring sustainable development in shrinking cities. This study investigates the regeneration potential of urban brownfields against the backdrop of population shrinkage and aging. Under the framework of Ecosystem Service Theory, this study adopts the Fulaerji District of Qiqihar City as a representative case, integrating its four key categories of ecosystem services into a three-dimensional “economic–social–environmental” evaluation framework. This approach facilitates the transformation of Ecosystem Service Theory from a conventional post-regeneration evaluation tool into a pre-regeneration framework for assessing potential and determining site prioritization. A tripartite evaluation system was constructed, integrating economic vitality (e.g., the population shrinkage index, the proportion of the elderly population, and transportation accessibility), social culture (e.g., the industrial heritage proximity index), and ecological regulation functions (e.g., proximity of green spaces and importance of ecosystem services). Leveraging multi-source geospatial data, land surveys, and field inspections, 12 candidate brownfield sites were identified. GIS spatial analysis and the Analytic Hierarchy Process (AHP) were employed to decipher their spatial distribution patterns and comprehensive potential grades. The findings reveal the following: (1) The evaluation results exhibit distinct spatial characteristics: high-potential sites, clustered near transport hubs and policy-supported zones, demonstrate multi-dimensional advantages, while low-potential sites, constrained by aging demographics, poor accessibility, and ecological vulnerability, are predominantly located on the urban periphery. (2) Correlation analysis between potential grades and various evaluation indicators, combined with a cross-comparison of population shrinkage levels and average values of other evaluation indicators across different potential grades, reveals that neither the population shrinkage index nor the elderly population proportion exerts a systematic negative impact on industrial brownfield regeneration potential. This finding indicates that within specific urban development contexts, brownfield regeneration potential is influenced more by structural factors such as locational conditions, policy support, and ecological service functions than by singular demographic trends. This research provides both theoretical foundation and decision-making support for differentiated brownfield regeneration and spatial governance in population-shrinking cities.

Brownfield greening (BG) has become an important approach to addressing urban land scarcity, environmental remediation, and sustainable urban development. This scoping review analysed 116 English-language publications from the Web of Science and Scopus databases. The review identified five major research themes: pollution and remediation, regeneration design, brownfield characteristics and greening benefits, planning and decision-making, and stakeholder perceptions. Findings indicate a transition from contamination-focused studies towards integrated approaches emphasising ecological restoration, social values, and multifunctional green infrastructure. Research methods have evolved from qualitative case studies to interdisciplinary approaches involving spatial analysis, ecological modelling, scenario simulation, and participatory methods. Existing studies mainly focus on regenerated sites and site-scale analyses, while contamination and remediation processes are often insufficiently incorporated into planning, design, and ecosystem-service assessments. The review highlights the diverse ecological, social, economic, and cultural benefits generated by BG and identifies key research gaps, including the need to better integrate remediation into regeneration processes, to conduct long-term monitoring, to conduct comparative international studies, and to include evidence from underrepresented regions. Overall, BG is increasingly recognised as a multifunctional strategy for sustainable urban regeneration.