We study the dispersion and stability of carbon nanotube (CNT) suspensions under the electrostatic interactions. The potential energies of van der Waals (vdW) attractions between the CNT themselves are obtained on the continuum Lennard-Jones (LJ) model. The potential energies of electrostatic repulsions are based upon the Yukawa-segment model. We explore the overall interactions mediated by the vdW force and the electrostatic force between two identical, parallel CNTs. Consequently, we preliminarily confirm the accuracy and reliability of the electrostatic model.