Introduces the design and implementation of an online examination system for medical students. The system aims to improve the quality of teaching, motivate self-learning of students and update basic and clinical knowledge for medical students and young doctors. In the design of this system, we apply UML (Unified Modeling Language) models, such as use-case diagrams, sequence diagrams, activity diagrams, etc. Functional requirements are tracked from use-case models to component models through analysis and design models. The components derived from this approach form the components of the Model-View-Controller (MVC) architecture. It has proven very useful to smooth communication between medical professors and software developers, increase code reuse and accelerate development.