Abstract: Urban underground space is an essential resource for expanding urban land capacity, and its total scale has continued to grow. The authors evaluate the development quality of underground space in 22 representative Chinese cities using multi-source data and the entropy weight method, and they identify the primary driving forces with the geographical detector. The evaluation framework covers four dimensions: rail transit development, underground construction, underground-space resilience, and social development. Based on the comparative strengths and weaknesses, targeted strategies for improving development quality are proposed. Key findings are: (1) Shenzhen attains the highest development quality among surveyed cities. Within the evaluation system, underground-space resilience receives the highest weight, with economic resilience emerging as the most influential single indicator. (2) At the macro level, economic resilience is the primary driving influence; strengthening its coupling with commuting support and population dynamics is essential. For megacities, prioritizing the interaction between institutional-organizational resilience and spatial integration while advancing economic resilience is recommended. For large cities, increasing investment in scientific research and education is advised. (3) Cities in the intermediate stage of economic resilience should focus on improving interactive resilience factors. Institutional-organizational resilience should be kept below the threshold of 6.699%. When population density exceeds 8 143 persons/km², improving the adaptability and utilization efficiency of underground-space facilities becomes particularly important.

Key words: urban underground space, development quality, entropy weight method, geographical detector, driving forces