A general strategy to disperse and functionalize pristine carbon nanotubes in a single-step process is developed using conjugated block copolymers. The conjugated block copolymer contains two blocks: a conjugated polymer block of poly(3-hexylthiophene), and a functional non-conjugated block with tunable composition. When the pristine carbon nanotubes are sonicated with the conjugated block copolymers, the poly (3-hexylthiophene) blocks bind to the surface of de-bundled carbon nanotubes through non-covalent pi-pi interactions, stabilizing the carbon nanotube dispersion, while the functional blocks locate at the outer surface of carbon nanotubes, rendering the carbon nanotubes with desired functionality. In this paper, conjugate block copolymers of poly(3-hexylthiophene)-b-poly(methyl methacrylate), poly (3-hexylthiophene)-b-poly(acrylic acid), and poly(3-hexylthiophene)-b-poly(poly(ethylene glycol) acrylate) are used to demonstrate this general strategy.