Graphene (GR) films have been demonstrated as great promising materials in many fields, including battery electrodes, supercapacitors, electronics and functional composites. However, the applications of GR films are limited either by their brittleness, small size, or by their unsatisfactory electrical conductivity. Here, we report an efficient methodology for fabricating large size, flexible and electrical conductive GR films, which mainly involves compression of the graphene oxide (GO) aerogels into porous GO films as well as reduction of GO films into porous GR films via chemical or thermal route. The densities of GR films can be adjusted by controlling the concentration of GO dispersion precursor. The porous GR films exhibit high electrical conductivity up to 5.5x10(3)Sm(-1) and favourable electromagnetic interference (EMI) shielding effectiveness up to 50dB in a wide frequency range. The high porosity, excellent electrical conductivity and remarkable EMI shielding effectiveness enable the GR films to be greatly useful in lightweight conductive films, electromagnetic shielding materials and flexible batteries and supercapacitors.