Abstract: Combustion characteristics and thermal dynamic characteristics of inferior coal and core board mixture in O₂ and N₂ atmosphere were studied with O₂ concentration of 20％, 30％, 50％, 70％, 90％ respectively. With the increase of O₂ concentration, DTG curves tend to move to lower temperature region. Also, ignition temperature, maximum weight loss rate and its corresponding temperature, the temperature of burnout, and synthetic combustion factor of mixture, are compared. The results indicate that O₂ concentration can significantly improve the combustion conditions. Apparent activation energy of the fixed carbon combustion section is put into the calculation and analysis, which shows that the apparent activation energy increases with the increasing O₂ concentration. In order to quantize combustion condition internal and external, definition of combustion enhancement factor(C.E.F.) is put forward. In selected fixed carbon combustion segment, C.E.F. increases rapidly with the increase in O₂ concentration, which proves the positive role of oxygen concentration on combustion. There are kinetic compensation effect between C.E.F. and apparent activation energy.