In this paper, we used UML method to complete the whole hospital information system analysis and design. It is described the system and determine the requirement of system’s function. It also completes the system’s architecture design and detailed design and implement to the system. The main idea of thesis is as follows: 1）It adopt UML to object-oriented the modeling hospital information system, and will be a good way to solve a few questions from hospital information system in nowadays. 2）It moves around the main ideas of RUP (use-case driven, architecture-centric, iterative and incremental). At the beginning of get demand, through the system analysis, system design, until to the final of the system implementation. It adopts the stepwise deduction to go deep into the way of refining organization to anatomize the whole the process of the hospital information system. Through the success of the hospital information system modeling to prove that the core idea of the UML-based on RUP modeling techniques is practical in the development of large-scale of application systems. At the same time, it also prepared to provide a better reference and instance for the project or team to adopt this technology.