In this study, lignite char-water mixture (LCWM) was prepared with char from lignite pyrolysis at different temperatures. Sodium lignosulfonate (SL), naphthalenesulfonate formaldehyde (NSF) or the mixture of SL and NSF was used as dispersant in the preparation of LCWM. The effect of dispersant on fluidity and stability of LCWM was investigated at the fixed char loading of 60 wt.%. The results showed that the mixture of SL and NSF as dispersant can effectively decrease the apparent viscosity to less than 400 mPa s and enhance the fluidity of LCWM. The optimum dispersant content for four lignite char samples was examined and the adsorption behaviors of SL, NSF and their mixture on the char surface were also discussed. Meanwhile, the static stability of LCWM was investigated with sodium salt of carboxymethyl cellulose as stabilizer. (C) 2010 Elsevier Ltd. All rights reserved.