Abstract:Based on the notion of network motif and the superfamily identification method, this paper systematically detects the characteristics of building blocks and superfamilies for several national critical transportation networks in China. Results show that transportation network motifs are pre defined and non random local patterns, which are more probable to represent economic cost, technological constraints, and geographical limits in network structures. Moreover, the 4 node subgraph concentration rank of the networks can be divided into two kinds, each corresponding to geography network or service network. Furthermore, based on 4 node subgraph ratio profile(SRP), the transportation networks can be classified into two types of families, which may allow an easily interpretable view of the transportation system.