A composite material having a high thermal conductivity and a small thermal expansion coefficient, which is obtained by impregnating a porous graphitized extrudate with a metal; the composite material having such anisotropy that the thermal conductivity and the thermal expansion coefficient are 250 W/mK or more and less than 4.times.10.sup.-6/K, respectively, in an extrusion direction; and that the thermal conductivity and the thermal expansion coefficient are 150 W/mK or more and 10.times.10.sup.-6/K or less, respectively, in a direction perpendicular to the extrusion direction.