论述地理空间元数据在地理空间数据共享和管理中的重要作用，分析地理空间元数据研究的现状及当前所面临的困难，指出地理空间元数据在空间的语义表达和空间数据表示上存在的缺陷，及其对地理空间元数据深入研究和地理空间元数据标准化进程的影响，基于XML／RDF（Resource Description Framework,可扩展的互联网标记语言XML的一种应用元语言）技术提出利用XML／RDF表达地理空间元数据的思想，以美国FGDC的元数据标准为例，提出基于XML／RDF的地理空间元数据表达方法，即通过XML表达地理空间元数据解决元数据的集成，通过RDF表达地理空间元数据解决元数据的语义问题，从而为元数据的共享提供了新的思路，最后指出基于RDF的地理空间元数据表达方式的重要作用及其管理方式。

Metadata of geospatial data is the description of geospatial related data sets and information resource. With Geospatial metadata, geospatial data users can quickly learn about the name, quality, scale, data structure and so on. In particalar geospatial metadata has been extended from a method of data describing and indexing to one of the essential tools which has been involved into the whole internet information procedure, including data finding, converting, managing and using. Geospatial metadata is one part of the core contents of digital earth and geographic information infrastructure. Nowadays, because of the important role bring played by geospatial metadata, it has become a new research topic in geographic information system field. However, the most researches on geospatial metadata is on its standard establishment, management and application. In fact, how to express geospatial metadata is the base of its standard and management. The authors analyze the current situation and the obstruction faced with on metadata research procedure, and point out the limitation existed on how to express geospatial metadata structure and syntax. This paper has made a study on how to express geospatial metadata and its standardization. The authors present a new metadata expression idea based on resource description framework (RDF), a kind of application language of extensible mark up language (XML). This paper also give an example based on FGDC metadata standard, at the same time, get a new method of geospatial metadata expression based on XML/RDF. The new expression method with XML can realize the integration of metadata, and while expressing geospatial metadata with RDF resolve the syntax problem of metadata expression. At the end, the paper shows the vital functions and the managing methods of geospatial metadata expression based on RDF.