Exhaustion of profitable coal resources makes for need of innovation including underground coal gasification ( UCG) �� One of the most important problems of UCG is evaluation of the combustion area in underground coal seams�� Physicochemical parameters of coal��in a whole��and coal mineral substance are changed under heating and combusting�� Thermo-chemical conversion of coal mineral components has an effect on magnetic characteristics of coal seam and can be used for real-time control of combusting area�� To this guessing check laboratory experiments have been made as an activity of the Far Eastern Federal University�� Our investigation based on a theoretical analysis and laboratory simulation tests�� Typical results of the laboratory experiments are presented below�� Under heating coal thermo-chemical magnetization is forming�� Coal's magnetic parameters varieties from anti-ferromagneti�� to ferromagnetic�� Anti-ferromagnetic pyrite and siderite presented into coal mass is transformed into magnetic hematite and magnetite under heating�� Therefore��geomagnetic is expected to be a useful geophysical tool to for evaluation of combustion volume and its migration for underground coal gasification��