Abstract: International Image Interoperability Framework (IIIF) is developed by a community of GLAM (Galleries, Libraries, Archives and Museums) with the purpose to address the “imagesilo” issue. It has also become the implementation standard for the management of image resources in cultural heritage institutions. IIIF defines four application programming interfaces, which facilitate the integration, sharing and interoperability of image resources in multiple sources and different formats. This paper adopts literature review and case study as research methods, and introduces the framework of IIIF APIs, focusing on the curatorial API and discovery API. Curatorial function, in particular, has changed the IIIF workflow. Under the guidance of the existing technology and future development, IIIF is useful in building userdriven image sharing platform, constructing the semantic image framework, sharing large-size images and being the tools for digital humanities.