In order to make clear the regulation of the combustion and the heat-transport process of fire-retardant treated wood, the combustion of untreated, fire-retardant solution soaked, and fire-proof paint coated white pine (Pinus bungeana) and northeast China ash (Fraxinus mamdshurica') wood as well as the rising process of temperature at different sites in wood were measured, taking a multi-function fire-proof experiment oven to simulate the typical process of fire. The results showed that: (1) There were five stages in the rising process of the internal temperature of untreated, fire-retardant solution soaked, and fire-proof paint coated wood during the fire; (2) The carbonization rate of wood decreased by 21.1%-35.6% and the rising speed of internal temperature also declined greatly when wood was soaked in fire-retardant solution or coated with fireproof paint; (3) The carbonization rate of white pine was 8.5%-17.4% higher than that of the northeast China ash; (4) For untreated wood, the carbonization rate in tangential direction was 5.8%-10.5% higher than that in radial direction; (5) The internal temperature of wood varies with the developing direction of combustion.