Nanoparticles show a variety of size-dependent properties due to the dramatic changes in the ratio of surface area to volume. The characteristics of nanoparticles different from the bulk material make the properties of the powders composed of these nanoparticles attract more attention. The heat transfer in the powder composed of nanoparticles is experimentally investigated in this paper. The powder is wrapped up in the slender tube made of insulating material. One end of the slender tube filled with powder is maintained at low temperature and the other end is kept at room temperature. The temperature histories at two different locations in the slender tube are recorded using thermalcouples. The results show that the heat transfer depends on the bed porosity and the thermal conductivities of the solid and the gas. The pressure on the Al powders enhances the rate of heat transport due to the decrease of the bed porosity and a small fraction of gas.