Abstract
Data object modeling is considered the most effective style in data manipulation. This style provides the ability to decompose complex systems into parts, these parts can be manipulated simply, understanding, accuracy with easy updating reducing run time errors supporting ability of design languages such as Unified Modeling Language UML. The research implements modeling of Depreciation system using UML and its tools such as (objects, classes, link & association & aggregation, generalization, drive data, class diagram, packages, logical horizon) and obtaining the general schema for classes to be converted to an used application using data base programming language.