Conducting polyaniline has been widely used in conductive additive, supercapacitive electrode, electrochromic device, and so on, owing to its good opt-electronic performances. Various carbon nanostructures including zero-dimensional fullerene, one-dimensional carbon nanotube, and two-dimensional graphene have unique nanostructures, good conductivity and strong interaction with polyaniline. Combining conducting polyaniline and carbon nanostructures will endow polyaniline enhanced opt-electronic performances. In this report, we demonstrate various approaches to prepare polyaniline/carbon nanostructure composites and study their electrochromic and supercapacitive performances. A general preparation procedure is that the carbon nanostructures are first functionalized by chemical with aniline group, then the functionalized carbon nanostructures are introduced into the chemical polymerization system of aniline. The resulted composites include water soluble solutions (PANI-C60, PANI-CNTs and rGO-PANI) and nanopowder (PANI-C60 and rGO-PANI). The solutions are spin-coated on ITO glass for electrochromic properties testing. The nanopowders are used as the supercapactive electrodes. The results show that with incorporating of carbon nanostructures, the electrochromic and capacitive performances of polyaniline have been enhanced in some extent. The improvement mechanism of the opt-electronic performances are related to the high electron conduction and fast ion transportation of nanocomposites induced by the high conductivity of carbon nanostructures and loose molecular packing aggregation.