The effects of dispersants on stability of the red pigment dispersions in alcohol-soluble ink for white-board-marker have been studied in this paper. The non-ionic surfactant fatty alcohol polyoxyethylene ether (AEO-6), polymeric dispersant polyvinyl butyral (PVB), polyoxyethylene polyoxypropylene block copolymer (F68), polyvinyl pyrrolidone (PVP) and its mix respectively with AEO-6 were investigated regarding this purpose. The stability of the red pigment dispersion was evaluated by centrifugal separation-absorption spectrophotometry tests and particle size analysis. And in order to explore the interaction between polymer and surfactant, the rheological behaviour of the dispersions was tested. Finally, the dispersants which made the dispersion with good stability were used to prepare red white-board-marker ink, and the stability of ink was characterized through rheological tests and particle size analysis. The results show that the stability of the red pigment dispersions is considerably improved by the polymeric dispersants. Particularly the dispersion with the mass fraction of 1% PVB has exhibited excellent stability properties. In the pigment dispersions with the mixture of polymer and AEO-6, polymeric dispersants play a significant role, AEO-6 does not play a main role. The red white-board-marker ink which dispersed by PVB has excellent stability properties. This result is consistent with the red pigment dispersion.