地球观测数据共享是地球科学和相关学科科研活动中非常重要的基础性工作，是对地观测信息生命周期中的重要环节。受到由资源提供者、资源消费者和资源加工者组成的社会生态系统发展变化的影响，共享模式经历了无共享、项目共享、部门共享、社会共享等渐进的4个发展阶段，并呈现出区域差异和阶段差异。地球观测数据共享的概念体系包含数据开放、数据共享、数据互联等不同层次的问题，并受到信息技术等使能技术的驱动。其中开放性代表数据在网络中可被访问的状态，共享性是对于数据重复使用的授权和模式，互联性则是强调可共享数据资源在科学含义上的相互理解。而地球观测数据共享的技术体系则包含数据开放技术、数据共享技术和数据出版与引用技术。目前地球观测领域的数据共享正在经历巨大的文化、政策、技术和应用变革，下一代的地球观测数据设施集中体现了数据的共享和协作，并将呈现国际化、多学科化、标准化、设施化、大数据化和公众社会化等新的技术特征，将对相关科学活动产生重大影响。

Earth Observation data sharing plays fundamental role for earth science research, which is an important part in the EO data lifecycle. Affected by the changing of data sharing ecosystem with resource provider/consumer/processor relationship, the sharing mechanism is presenting itself in sequential phases of rear-sharing, project-sharing, department-sharing and public-sharing. Information technologies have always driving the changing of scientific agenda of data sharing, which now can be understood as data open, data sharing and data link. Open of data means the condition of accessible via network, sharing of data means authorized method to reuse data, and link of data means scientific cross-understanding and cooperation of different data resources. Comparing with the evolution history of data sharing policy in USA, China needs to improve its sharing mechanism to be multi-win and sustainable by a dynamic adjusted data sharing socio-ecosystem. The present technical framework of earth observation data sharing is built up with implementation components of data open, data sharing, data publication and data citation, and so on. Under the revolution on cultural, political, technical and application factors for earth observation data sharing, the Next Generation EO Data Infrastructure based on deeply and widely sharing is becoming a reality. The new technical trends of earth observation data sharing as Globalization, cross-disciplinary, standardization, facility-oriented, big-data and public-engagement, will heavily change the related scientific activities in near future.