In this paper, MnO2·xH2O/carbon aerogel (CRF) composite electrode materials were prepared by a chemical co-precipitation method. The structure and morphology of MnO2·xH2O/CRF were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that carbon aerogel was an amorphous material with a pearly network structure, the MnO2·xH2O powders possessed, a nanoscaled structure, and thus the MnO2·xH2O/CRF composite materials were nano-sized particles with a relatively high specific surface area. Electrochemical performance of the composite electrodes with different ratio's was studied by cyclic voltammetry and galvanostatic charge/discharge measurements. The results indicated that MnO2·xH2O/CRF composite electrodes had good electrochemical performance, high reversibility and high charge–discharge properties. Moreover, when the loading amount of MnO2·xH2O was 60%, the composite material has a high specific capacitance of 226.3Fg−1, while the capacitance of carbon aerogel electrode alone was 112Fg−1. Besides, MnO2·xH2O/CRF composite supercapacitors showed a stable cycle life in the potential range of 0–1.0V and retained 90% of initial capacitance over 400 cycles.