Abstract: The objective of the study was to design and implement the emergency information system based on cognitive task analysis. Firstly, we carried out a survey on the current information systems in the emergency department in our hospital to identify the needs and key issues in the development of emergency information system. Secondly, based on cognitive task analysis, we tried to identify the key links during the emergency services as well as the potential measures that are able to improve the healthcare efficiency and protect patients' safety. Finally, we successfully completed the design of the emergency information system. Results showed that the currently available emergency department information system had gradually been out-of-dated and needed improvement. By thoroughly analyzing the core needs of the emergency services, we found the key issues to be addressed in the new information system and developed the new architecture of emergency information system in our hospital. The emergency department has unique features and needs supports from a more sophiscated information system. In our current study, we successfully developed a new information system that is suitable for emergency services based on cognitive task analysis.