Summary form only given. Carbon nanotubes powders were synthesized by using chemical vapor catalytic deposition method. Further purification was performed by using sonification method. A printable carbon-nanotube paste was made by mixing carbon nanotubes with inorganic binder, intensifier, dispersant, and emulsification. The physical and chemical characteristics of this paste have been investigated. The solid content ratio is about 25% after heat treatment to remove the organic elements. The SEM image indicated that the granularity had attained the nanometer degree. We also test the viscosity and resistivity of the paste with different proportion. The field emission characteristics were measured in a diode structure. We summarize the ingredient proportion of the carbon-nanotube based paste. The results show that the field emission properties of the cold cathode formed by this CNT paste are excellent, even fired at a high temperature. This printable carbon nanotube based paste is suitable for field emission display.