Bus reservation system had actualized in different nations for years, at first from manual to automated reservation system. Online bus ticketing and reservation administrations are adequately expanding in the market since it was propelled by Park May. Now, numerous individuals and organizations are beginning to gain insights of the express bus reservation system. Considering the bus ticket reservation system that has experienced a constant development in the recent years, nevertheless the means for their specifications are still underdeveloped. The Unified Modeling Language (UML) is a language for the specification, visualization and documentation of object-oriented software systems. There is a lot of potential value in UML and diagrams in general. Existing UML diagrams can be utilized to helpfully display conduct. Therefore, in order to understand the development of bus reservation system, it is important to understand what the requirements are on the complete web based bus reservation system. Analyzing the web based bus reservation system by using UML diagrams. Consequently, the nature of theoretical models legitimately influences the nature of the comprehension of the application space and the nature of the last programming items that are at last dependent on them. In this study, we present (web based bus reservation system-UML), the proposed extension to UML covers aspects of use case diagram, sequence diagram, activity diagram and class diagram of the web based bus reservation at the various views and diagrams of UML.