Mobile Cloud Computing for Distributed Disaster Information System in Challenged Communication Environment Serious disasters have been annually occurring in Japan. For example, in the Great East Japan Earthquake that occurred on March 11, 2011, communication infrastructure was seriously damaged over a wide area. From such a situation, more resilient network infrastructure that does not stop under challenged communication environment is required. In this paper, we propose a disaster information system that can flexibly deal with failures of the server group and respond to rapid load change. We construct the disaster information system based on the cloud computing technology. In addition, we develop a dynamic allocation of server resources in accordance with the load change on the system so that it makes possible to take full advantage of the resources in the disaster areas. Also, by introducing a mobile cloud and DTN protocol, our system can realize rapidly sharing disaster information even though the communication breakdown area occurred.