元数据是营数字地球的关键技术之一，是数字地球中实现空间信息共享的主要解决途径之一，它与空间信息的共享是密不可分的。从数字地球的角度出发，对空间元数据的定义，在数字地球中的重要作用，管理模型及其解决方案和应用等方面进行了较为详细的研究，并给出了基于一种方案的具体实现和示范系统，为数字地球中的信息共享提供了可行有效的解决途径。

Metadata is one of key technology of constructing Digital Earth, and a main solution of implementing spatial information sharing in Digital Earth. In this paper, the definition, important role in Digital Earth, content, management model and its solutions, and application of Metadata have been researched in detail. And based on one of solutions, demonstration system of management model of Metadata have been achieved, and introduced here. It provides a feasible and practical way to spatial information sharing in Digital Earth.