Spontaneous combustion of commercial coal seams is common in exploration of coal field, which woutd impact directly on exact calculation of coal reserves because of the loss from spontaneous combustion. In order to determinate the exact location of complete combustion borders and semiburning borders, it is accessible from interpretation of magnetic data obtained from ground magnetic survey to locate coal spontaneous combustion borders indirectly based on a certain intensity of mag- netic anomalies of thermoremanent magnetism between the roof and foot beds of coal seams after coal combustion. According to interpretation of anomalies from ground magnetic survey by actual meas- urement in a coal field in Northern Shaanxi province, a summary of effective determination of coal combustion borders by high-precision magnetic survey has been made and verified by drilling, which would provide a source of reference for determination of combustion borders in future.