Carbon nanotube (CNT) has been intensively studied as supercapacitor electrode materials due to their high mechanical strength and excellent electrical conductivity. However, CNT with limited accessible surface area has low specific capacitance, which limits its application and development in supercapacitor. Herein, we have designed a thin N-doped porous carbon layer-modified CNT nanocomposite by template-free method. In this process, 3-aminophenol and formaldehyde rapidly self-assemble on the CNT in the presence of cationic surfactant CTAB, forming the composite of 3-aminophenol/formaldehyde (3-AF) resin and CNT. Due to the different polymerization degree of inside 3-AF resin, the soluble 3-AF resin oligomer was removed by acetone to form porous 3-AF resin and CNT@N-doped porous carbon (CNT@N-PC) was obtained by annealing process. The CNT@N-PC exhibited abundant porous structure, high specific surface area of 940m(2)g(-1), excellent specific capacitance value of 224 Fg(-1) at 1 Ag-1 and good cycle stability, demonstrating its potential as supercapacitor electrode materials.