Disclosed is a carbon nanotube powder, including a carbon nanotube averagely mixed with a dispersant, wherein the carbon nanotube and the dispersant have a weight ratio of 30:70 to 90:10. The carbon nanotube has a diameter of 10 nm to 100 nm, and a length/diameter ratio of 100:1 to 5000:1. The dispersant is an alternative copolymer, a block copolymer, or a random copolymer polymerized of a solvation segment (A) and a carbon affinity group (B). The carbon nanotube powder can be blended with a thermoplastic material to form a composite, wherein the carbon nanotube and the composite have a weight ratio of 0.5:100 to 50:100.