 Geoportals are web-based solutions for open spatial data sharing and online geoinformation management, with potential advancements according to the digital earth vision and implementation. This paper reviews literature on geoportals, summarizes approaches for discovering and accessing earth observation data and geoinformation, identifies challenges in terms of functionalities, technologies, and big data support from Chinese geoportal cases, proposes solutions and recommendations based on international and Chinese experiences, and highlights the potential of geoportals to lead to a full-fledged online digital earth system for better data sharing and dissemination. This article was offered by Hao Jiang, John Van Genderen, Paulo Mozzetti, and others.