Coal gradually changes into graphite accompanied by the process of chemical constituents progressively simplifying and structure ordering, which shows the characteristics of periodic and differences.This paper summarizes the exterior conditions (temperature,pressure,time) and interior factors (macerals,types and amounts of minerals) from the point of the evolution of macromolecules.The achievements and shortcomings of high temperature-high pressure experiments at home and abroad have been analyzed,and conclude that it has important significance to comprehensively understand the mechanism of coal metamorphism and graphitization.It is necessary to combine the geological survey and simulations to further discuss the effects of temperature,pressure,macerals and minerals etc.on the graphitization.
