Carbon aerogels are prepared by a sol-gel process. By controlling the mass ratio of reactants and the molar ratio of resorcinol to catalyst (R/C), carbon aerogels with different microstructures can be developed. The electrical conductivity is measured by the van der Pauw method. The results show that the electrical conductivity increases with increase of both temperature and density of carbon aerogel. Cyclic voltammetry is a useful technique to investigate the electrochemical properties of carbon aerogel electrodes. The maximum specific capacitance of carbon aerogel electrode in H2SO4 electrolyte is similar to 86 F/g.