Solidification and melting of metallic materials are crucial phase transformation in the metal forming process. When metallic materials in bulk volume are dispersed into infinitesimal droplets in microsize or even nanosize, significant changes in the solidification and melting processes can occur due to the size reduction of the materials. Obviously, these changes will dramatically influence the structure and service performances of the metallic materials. In this process, fundamental research on the scientific issues and the preparation techniques and characteristic methods for metallic droplets are involved. This article summarizes the research activities and accomplishments of the group in solidification and melting characteristics of infinitesimal droplets. Besides, the future development of research in this field is prospected.