Abstract: Knowledge flow between regions has gradually become the pillar of allocation of innovative resource in spatial and promotion of national integrative innovation. Using the “flowing” date of the transformation of patent rights between the cities as origins and destinations since 2008, the shortcomings of document analysis in patent citation studies are avoided. Applying a spatial interaction model and extending the sole geographic proximity to multi-proximities which contain technological proximity in overall level and structural category and institutional proximity, the cities individual dummy variables are estimated to describe the regional capacities in China’s major cities. As the empirical result shows, there is a critical point between 1000 to 1500 kilometers in the interactive effects in China’s knowledge flow, and technological proximity is confirmed in 2 aspects. Meantime, the cities with higher regional absorptive capacities spatially appear to cluster to be circles or belts.