Composites of polyaniline (PANI) and a unique ordered mesoporous carbon MPC which possesses small pores inside the carbon walls have been prepared. The monomer (aniline) of PANI is firstly soaked in the small pores inside the carbon walls and then confined in the primary mesochannels as well with increasing the concentration of aniline in the soaking solution. After the following in situ polymerization, composites of PANI and MPC with bicontinuous interpenetrating framework are formed. The composites show significant redox activities at potentials negative to 0V vs. Hg/HgO in a strong alkaline solution, which is unusual for PANI and PANI based composites as PANI usually loses its electrochemical activity at pH>4. The specific capacitance of the composites is as high as 400Fg−1 at a high current density of 1Ag−1 in the potential range of −0.7 to 0V, which is twice higher than that of the host MPC. The capacitance only decreases about 9% when the discharge current density increases from 1 to 20Ag−1, indicative of excellent rate capability. Therefore, the composites are very promising for the application as electrode materials in supercapacitors, especially as materials for negative electrode in hybrid supercapacitors.