Objective To clarify the temporal and spatial evolution characteristics of landscape connectivity in major cities in China and its differential driving mechanism, so as to provide a scientific basis for the construction of urban ecological network and biodiversity conservation.

Method Based on the land use data of 31 cities in China from 2000 to 2020, the probability of connectivity index (PC) was calculated by using the Graphab model to reveal its temporal and spatial variation. Key drivers of landscape connectivity were identified by correlation analysis and principal component analysis.

Result (1) The landscape connectivity level of 31 cities exhibited a spatial pattern of "high in the West and low in the East", and the overall trend was downward, with a decrease of 4.8%. Urban expansion was significantly negatively correlated with landscape connectivity, and different city types displayed diverse coupling pathways. (2) The proportion of blue-green space was the primary positive factor affecting landscape connectivity, with the highest correlation (r = 0.69), which played a key role in supporting the ecological network structure, and exhibited a nonlinear relationship with PC. Urbanization indicators such as construction land area, population density and temperature showed negative correlations. (3) The distribution of cities in the two-dimensional principal component space displayed distinct regional clustering. Cities in the southwest and northwest generally possessed a favorable ecological foundation, while those in East China, South China, and North China were concentrated in areas with high urbanization levels.

Conclusion The long-term evolution trend of urban landscape connectivity has been quantified at the national scale, revealing that the evolution of landscape connectivity is driven by both natural geographical conditions and urban development patterns. The results provide a theoretical basis for optimizing ecological networks and guiding region-specific strategies.