The high-temperature nitridation treatment and hydrothermal solid-gas reaction are employed to fabricate nitrided TiO2 nanoparticles/nanotube arrays for supercapacitors, to optimize their electrochemical properties. The annealing temperature in NH3 atmosphere was found to affect the chemical constitution and electrochemical performances of as-annealed TiO2 nanotubes. Attributed to the co-contribution of high-temperature nitridation treatment and nanoparticles/nanotube structure, the TiO2 nanoparticles/nanotube arrays annealed in NH3 atmosphere at 700 degrees C demonstrate the highest specific capacitance of 90.5 mF cm(-2).