Spherical PVC paticles and Short fiber-like PE particles were used as the polymeric matrix and spherical Ni particles and platelike Cu particles were added to these matrix to make the composite specimens. The size ratios of the polymeric particles to the metallic particles were set as 1,5, and 20 and the compacting pressures were 100-1, 500kg/㎠. Varying the shape of particles, compacting pressures, temperature, and the electrical specific resistivities of these specimens were measured. A drastic fall in the electrical resistivity at a critical volume percent of metallic particles, Vc was observed and remarkable changing of Vc with the particle size ratio was also observed. When the sperical metallic particles were used, the resistivity showed a sudden increase near the glass transition temperature of the polymeric matrix where the concentration of metallic particles was lower than Vc. However, in the case of higher content of metallic particles then Vc, there was no marked change in electrical resistivity. The specific resistivties of the composites were not effected by temperature and compacting pressure the plate like Cu particles were employed.