We report fabrication of reduced graphene oxides (RGO) papers using thermal reduction by vacuum-assisted for thermal exfoliation and in situ reduction of graphene oxide (GO) at temperatures as low as 180 °C. The conjugated sp2-carbon structure of GO was restored throughout the reduction process, and the thermal stability of the RGO papers was substantially better than that of the GO paper, according to Raman analysis and thermogravimetry analysis (TGA). The RGO paper that was reduced for 24 h exhibited the highest electrical conductivity of (29.3 ± 0.4) × 103 S m−1 at 180 °C. As the reduction degree of the RGO paper deepens, the thickness of the sample gradually decreases, indicating that the conduction type of RGO paper can be controlled by regulating the reduction degree. Thus, we demonstrate a simplified fabrication way for flexible conducting RGO paper of significant application potential as electrodes in a variety of devices.