Abstract: Based on the general thermal conducting principle of metal，inorganic nonmetallic materials，and polymer materials，two kinds of thermal conducting mechanisms of polymer/heat conductive filler composites were introduced，i.e.，thermal nets chain mechanism and thermalelastic combination mechanism. These mechanisms could explain various phenomena of heat conduction in polymer composites. Some thermal conduction models suitable for fiber and grain filled polymeric composites were presented. Effect of resin，heat conductive filler，and temperature on the thermal conductivity of polymer composites was discussed.

Key words: thermally conductive polymer, composite, thermally conductive mechanism, thermally conductive model, affecting factor