Abstract: Abstract：Analyzing intercity relations from the perspective of urban networks is an important way to understand the spatial structure and functional relation of regions. Urban networks are multiplex: urban networks constructed by different intercity flows might not have the same structure. In this study, four kinds of urban networks of the Yangtze River Delta were constructed, that is, the Internet network, transport network, corporate network, and knowledge network. Based on social network analysis and nodal region analysis, the structure of these four urban networks were comparatively explored through the lens of local node and dyad, global network and organization pattern, followed by preliminary explanation of their determinants. The results showed that: (1) The Internet network has a most balanced structure. Centered on Shanghai, Nanjing, Hangzhou, and Suzhou, it presents coordinated development organized by “one dominant city+three subdominant cities+hinterland”. (2) Transport network and corporate network are highly similar with a well-connected core region while two weakly-connected sides in the North and South. The flow triangle of Shanghai-Nanjing-Suzhou and the Z-shape flow corridor of Nanjing-Shanghai-Hangzhou-Ningbo are distinct in the core region. The northern side has weaker connectivity than the southern side. Both networks have three independent nodal regions organized by “single core city+surrounding cities”. (3) Knowledge network is sparsest and most polarized. The overall network is weakly connected except for the core region, displaying highly hierarchical development organized by “one dominant city+one subdominant city+two subordinate cities+peripheral cities”. (4) The discrepancies of these four networks are associated with geography, location, industry, academic resources and development strategies.