A carbon nanotube suspension uses water as the basic solvent added with dispersant, stabilizer, coalescing aid, adhesion promoter, and a carbon nanotube. The basic solvent and the above solutes form a low viscosity solvent with carbon nanotube suspending therein. Therefore, the carbon nanotube suspension is formed to serve as a source material of the electron emission source of a field-emission display. That is, the carbon nanotube can be coated on a surface for forming the carbon nanotube electron-emission layer.