Abstract: Now, there is a world-wide interest to use plant oil as substitute fuels of farm power. This paper, based on the auther's experience of many years' experiments, introduces the physical and chemical characteristics of plant oil used as fuels, including the combusting process in combusting chamber, the adaptability to different kind of diesel engines, short performance tests of various plant oil and the long period experiment of using rape oil as fuels, and briefly analysis the perspective of plant oil fuels.