Abstract: At present, object-oriented technology is widely used in GIS research and software development, besides of the advantages that object-oriented technology brings to software analysis and design, it also benefit the data modeling of GIS. UML-G, an OO modeling language for geographic information applications, is described based on the extension mechanism provided by UML. The extension approaches include stereotypes, tagged-values and constraints. In UML-G class diagram, these three extension approaches are used to define geospatial objects and geospatial relations. The representation in UML-G of four types of objects, i.e. simple spatial object, coverage object, complex spatial object and spatio-temporal object, is discussed. For each case, the model instance is described and proves that UML-G is an efficient modeling language for GI applications. Besides geospatial objects, the representation of spatial relations is emphasized. Based on the analysis of the spatial object property, spatial relations can be regarded as derived properties, so it is not necessary to identify them during the analysis phrase. Based on the discussion, two solutions are given, one can be applied in generic GIS-platform development, and another fit for the specific GIS application development. At the end, future research work of UML-G is listed, which includes the extension for OCL and the other diagrams, such as use case diagrams, collaboration diagrams, etc.

Key words: object-oriented modeling technology, UML-G, geospatial object, geospatial relation

摘要： 在分析其他学者的针对GIS的建立的OO(Object-oriented)模型基础上，基于目前已经成为建模技术标准的UML，并利用其扩展机制，包括构造型、标记值和约束，对UML进行扩展，定义了针对地理信息应用的面向对象建模语言UML-G，描述了UML-G的元模型，并采用UML-G对空间对象和空间关系的模型表达进行了研究，包括简单空间对象、覆盖对象、复合空间对象、时态空间对象以及空间关系的表现。通过分析以及相关实例的表述，表明UML-G可以很好地在GIS开发过程中使用，从而使得模型更加简洁并具有更好的表现能力。最后指出了进一步的研究方面。

关键词: 面向对象建模方法, UML-G, 空间对象, 空间关系