Abstract: Abstract The structures, electrical and thermal conductivity and their temperature dependences of the composites, which were prepared with polyethylene or polystyrene filled by polypyrrole particles, were investgated. It was found that the fabrication procedure inllu-ences the homogeneity of composite, the conductive threshold and characterization of the composites. The variation of thermal conductivity can be described by a series model. The relationship between the fabrication procedure, volume fraction of polymer particles strutures and conductive characterization of the composites was also discussed.