Modern society brought high demands on the quality of information systems, which require the use of modern methodologies and software to automate the process and reduce development time of the project and raise its quality. One of the most promising approaches in this direction is the Model Driven Development (MDD), that is an innovative approach for development of different software applications using models at different levels of abstraction and applying model transformation to code generation. The main objective of this paper is to present an approach for model-driven development of online air ticket reservation system based on UML.UML use case diagrams and class diagram are used to model the main requirements and data model of the system respectively in order to achieve reusable and portable models of the system. The developed UML conceptual data model is implemented in a MySQL based database. Finally, some conclusions are made.