Effect of pH value and dispersant of polyethylene imine (PEI) on dispersion of nano TiN in ethanol liquid was investigated by sedimentation volume and viscosity, surface electric characteristic of particles was measured by Zeta potential. Results showed that pH value and PEI concentration had an important effect on dispersion of nano TiN. Excellent dispersibility was obtained through adjusting PEI amount and pH value. It was found that PEI was an efficient dispersant for nano TiN to disperse in ethanol liquid. The dispersibility follows by electrostatic and space steric stability mechanism.