Abstract: Based on the complex network theory, SpaceL topology models of 2016 and 2021 Nanjing Metro network were set up, and the indexes as node degree distribution, average shortest-path length, network diameter and degree of connectivity were adopted to make a comparative study of their structural property, according to planar characteristic of the metro network. The results showed that Nanjing Metro Network of 2016 and 2021 had scale-free property, and the scale-free factor were 4.2 and 3.7 respectively, and the “fat tail” was more obvious in that of 2021; both the degree of connectivity of 2016 and 2021 were below 0.4, plus the network average shortest-path length were not below the log of the number of vertex, so the network had no small-world property; according to betweenness, the key stations change a lot in 2016 and 2021. According to the results, it is proposed that it be necessary to combine the flow pattern with the network static structure to identify the key nodes, the line-covering area should also be considered when measuring the developing stage of the metro network. The research was fundamental endeavor to reveal the robustness, vulnerability, resilience of Nanjing Metro Network, and to optimize allocation of resources，and to strengthen risk management.

Key words: Nanjing metro network, SpaceL topology model, node degree distribution, average shortest-path length, degree of connectivity