：元数据是各国政府开放数据行动计划的重要组成部分。文章在介绍W3C元数据标准DCAT（Data Catalog Vocabulary）、美国的“开放数据项目”（Project Open Data，POD）和欧盟的DCAT应用纲要（DCAT-AP）方案基础上，分析和总结了美国、欧盟和爱尔兰政府开放数据元数据建设的成果和特点。通过对比我国北京、上海和浙江三个地方政府开放数据元数据建设情况，认为我国政府开放数据的元数据建设应在政策支持及法律保障、体系完整和语义化方面加强工作，以克服当前在规范化、标准化和互操作上的不足。

Metadata is an important part of Open Data Initiative across the world. Based on W3C metadata standard DCAT（Data Catalog Vocabulary）, American Project Open Data (POD) and DCAT-AP of EU, this paper analyzes the achievements and characteristics of the metadata in the United States, European Union and Ireland. By comparing metadata schemas of Chinese local governments such as Beijing, Shanghai and Zhejiang, this paper points out that the metadata construction of China's OGD should be strengthened from aspects of policy support, legal protection, system improvement and adoption of semantic technology so as to overcome the drawback in the normalization, standardization and interoperability.