Urbanization in megacities has evolved dramatically from monocentric settlements to polycentric networks and the new socio-economic dynamics, with the previously inconceivable scale and population. Beyond the fascination for the youngest mega city in the world, Shenzhen in China, the point of this thesis is to diagnose the phenomena of fragmentation happens in the polycentric networks and to understand the processes, the incompatibilities and the potentials. Based on this discussion it aims to test a set of multi-scalar strategies of public space to integrate the polycentric networks at the large scale with the quality of local places. The thesis has actively involved the multidisciplinary reflections in planning, landscape, urban design and architecture, in which the body of knowledge is made by mapping the urban morphology in Shenzhen-Hong Kong megalopolis. It creates a framework from facts to proposals for comprehending the essence of megacity and exploring the approaches to improve the quality of it by the netowrk of landscape and public space.