Abstract: The technology of the dispersability and stability of ultrafine ATO conductive powder in water, as well as the influence of those parameters such as the types of dispersants and the adding amount, pH value and methods of dispersion on the preparation of ATO slurry, was discussed. The influencing factors can be optimized by diameter measurement, TEM observation and sedimentation experiment, and thus ATO slurry with good dispersability and stability can be finally obtained.