Abstract: In order to prevent impacts of postal industry emergencies on structure and performance of urban express networks, random and deliberate network failure models were proposed according to characteristics of such emergencies. Secondly, network connectivity, global network efficiency and local network efficiency were adopted as evaluation indicators of network vulnerability. Then, importance evaluation model was used to determine importance of network nodes and to decide node hierarchy which served as basis for deliberate attacks. Finally, models were verified with network data of an express delivery company as an example. The results show that vulnerability of global network is significantly higher than that of local network when central node is deliberately attacked. Vulnerability of these two networks is synchronized in the same case for transit nodes. Moreover, failure of a single node in turn has little impact on network, but cascading failure of nodes has a greater impact, while that of nodes of high importance suffering from continuous deliberate attacks can cause network to collapse quickly

Key words: emergency, express network, vulnerability, complex network, node importance