Mobile software technologies have become increasingly important in building disaster response system to cope with natural and man-caused emergency situations. In this paper we present a context-aware disaster response system that analyzes the contextual information of public users and disaster environment, and then delivers customized instructions in an appropriate format to the mobile handsets of the public users in a timely manner. Compared to traditional disaster response systems and approaches, the proposed system can greatly improves the timeliness and efficiency of the instructions in the response by utilizing context awareness and mobile software technologies. Supporting evaluation results are also provided based on experiments that have been conducted on a software prototype which is developed to validate the proposed system.