Abstract:At the Gathering to Celebrate the 60th Anniversary of the International Union of Geological Sciences (IUGS) in Zumaia, Spain, from October 25 to 28, 2022, the IUGS officially announced the list of the first 100 IUGS Geological Heritage Sites, a major outcome of International Geoscience Programme project IGCP- 731 coordinated by the International Commission on Geoheritage. Also the “IUGS Zumaia Declaration” was issued, calling for worldwide attention to the scientific research and management of geological heritage sites. It has received warm responses from the international geoscience community and the public. Based on the whole process of participation in this work, we systematically introduce the origin, development, selection procedure and process of the first 100 IUGS Geological Heritage Sites, as well as the definition and standards of IUGS Geological Heritage sites. We also identify the significance of these sites for scientific research and sustainable development, and prospect the future development of IUGS Geological Heritage Sites.