Abstract
Taking advantage of this opportunity when the first Thermal Engineering Division Conference of the JSME in the present century is going to be held, the author aims to summarize how the thermophysical property research on technically-important fluids did contribute a series of remarkable achievements in the field of science and technology during the past century. Emphasis will be given to the significant progress in thermophysical property researches on water substances and refrigerants followed by environmentally-acceptable alternative refrigerants. The former has brought electric power generation that was still a novelty a hundred years ago into the most essential energy supporting our current daily lives, while the latter has made it possible that human being could harness air-conditioning which was nonexistent in the beginning of the last century. All what we have learnt throughout thermophysical property researches over the last several decades will then be discussed so as to identify what we have to do for the present 21st century.
