The grain boundary region and pore play an essential role in nanostructured materials. In the present study, nanoporous (np-) Au prepared by dealloying (DA np-Au) is studied by means of the anelasticity measurement referring to the nanocrystalline (n-) Au prepared by the gas-deposition method (GD n-Au). In GD n-Au >0.99 (the subscript, >0.99, denotes the relative density of the specimen referring to the bulk density), the linear increase in the internal friction above 200K (Q>200 K−1) and a broad peak at about 100K (P L ) are observed. In GD n-Au 0.81 containing nanopores, broad peaks at about 220K (P H1 ) and 260K (P H2 ) as well as P L and Q>200 K−1 are observed. In DA np-Au 0.4 , P L , P H2 and no Q>200 K−1 are observed. Densification of DA np-Au 0.4 by pressing causes a significant increase in both P H1 and P H2 , and annealing at 360K cancels the effect of pressing. These results are discussed in the light of the characteristic grain boundary properties in nanostructured materials.