The development of cutting fluids is related to the progress of the metal machining field. The requirement to the performance of cutting fluids is varying due to the trends, and it is important to response to laws and regulations regarding chemical substances in Japan and overseas, and to consider the working environment. The basic functions of cutting fluids are lubricity, cooling ability and anti-build-up ability. Various performances based on these effective functions make it possible to contribute to productivity improvement in the machining field. On the other hand, the environmental problems relating with cutting fluids should be more considered. Many countries have laws and regulations such as PRTR in Japan, REACH in EU, TSCA in USA. Therefore, it is important to response them to prevent environmental pollution and risks for human health. In this paper, it is described the fundamental knowledge regarding performance and properties such as water miscible cutting fluids and straight cutting oils, and the environmental response based on the current trends as well as several requirements.