Provided are a conductive polymer-carbon nanotube composite including a carbon nanotube and a conductive polymer filled therein, and a method of manufacturing the same. The conductive polymer-carbon nanotube composite where a conductive polymer is filled in a carbon nanotube is manufactured by introducing a monomer of the conductive polymer into the carbon nanotube using a supercritical fluid technique and polymerizing the monomer. The conductive polymer-carbon nanotube composite is a novel nano-structure material which can overcome limitations that conventional materials may have, and thus can be applied to various applications such as sensors, electrode materials, nanoelectronic materials, etc.