An emerging polycentric spatial structure in China's mega cities has been confirmed in the literature, but few studies have addressed the linkage between the change in spatial structure and urban development policies. Using Beijing as a case study, this paper examines the role of urban polycentric planning in the polycentric evolution process from a morphological perspective. We observed that urban polycentric planning significantly promoted the emergence of a polycentric urban form in

more »

... metropolitan area from 2001 to 2010. Firstly, most of the planned subcenters were identified as real employment subcenters by a relative threshold method in 2001 and 2010 and comprised the majority of the employment subcenters. Secondly, the planned subcenters significantly increased their employment share and influence on employment and population distribution from 2001 to 2010, and their performances referring to these aspects were much better than the unplanned subcenters. Thus, our findings provide evidence that changes in urban spatial structure can be strongly affected by urban development policies, although it is determined by market forces in theory.