A novel carbon nanotube-carbon nanohorn complex produced by a method comprising step 1 for irradiating carbon nanotube placed in a liquid solvent with ultrasonic wave to disperse carbon nanotube into the liquid solvent, and step 2 for adding carbon nanohorn aggregate to the liquid solvent dispersed with carbon nanotube to thus remove the liquid solvent, whereby the surface of the carbon nanotube and the carbon nanohorn aggregate can be utilized more effectively and the availability can be enlarged.