Classical powder metallurgy followed by either hot isostatic pressing (HIPing) or repressing-annealing process was used to produce Cu-graphene nanoplatelets (GNPs) nanocomposites in this work.A wet mixing method was used to disperse the graphene within the matrix.The results show that a uniform dispersion of GNPs at low graphene contents could be achieved,whereas agglomeration of graphene was revealed at higher graphene contents.Density evaluations showed that the relative density of pure copper and copper composites increased by using the post-processing techniques.However,it should be noticed that the efficiency of HIPing was remarkably higher than repressing-annealing process,and through the HIPing,fully dense samples were achieved.The Vickers hardness results showed that the reconsolidation steps can improve the mechanical strength of the specimens up to 50％ owing to the progressive porosity elimination after reconsolidation.The thermal conductivity results of pure copper and composites at high temperatures showed that the post-processing techniques could enhance the conductivity of materials significantly.