OO-Structure Maker is a CASE-tool for object description of any application data both simple and complex-structured. This data is called an object-oriented information structure or OO-structure. OO-Structure Maker is a CASE-tool that provides visual design of object-oriented information structures. It generates a ready-to-use source code in Delphi and provides visual design of component, collection, collection items and persistent classes, their inheritance and composition relations. Any OO-structure supports: references between structure elements, referential integrity of the whole structure, data saving into a stream or file, modification flag as a Modified property for every class, properties copying method by overriding the Assign method for every class, adding data to the collections by overriding the Add method. OO-Structure Maker has 3 explorers of the object-oriented structure: Inheritance explorer, Property Explorer and Composition Explorer. A class of OO-structure can have 3 type of properties: information properties (pure data), object properties (pointers to composition parts) and reference properties (pointers to owners). OO-Structure Maker uses UML-like language. OO-Structure Maker is fully integrated with Delphi 5, 6, 7.