Petroleum Refining Engineering is a branch of chemical engineering which is essentially the application of Chemical Engineering in oil refining technology. Petroleum Refining Engineering is based on Chemical Engineering and Basic Chemistry. It is difficult to have an in-depth understanding and grasp for oil refining technology if you are lack of solid theoretical basis. The research object of this subject is complex mixtures whose components are very much. In characterization of the physical and chemical properties, the characteristics of complex mixtures should be considered. It is the main task of this subject how to efficiently and reasonably process crude oil into various petroleum products.