This special issue is an output of the research program "Molecular Engineering of Coal-Supramolecular Structure and Novel Utilization Technology, 1996-2000". The project was organized by and cooperated with The 148th'Committee on Coal Utilization Technology, JSPS. To provide incentive for coal science, the majority of the members in this project are young researchers who well keep the research activities alive in the 21st century. The program concentrates on the primary and network structures and molecular association of coal. Moving toward tailored reactions, such as enzyme catalysis, investigations involve the supramolecular chemistry of coal.