Abstract: To prepare the coal slurry with alkali black liquor replace additive and water, analyzed the stability and temperature change feature of black liquor coal slurry, the law of change of rheological behavior with the time goes on, the effect of shearing on rheological behavior, and also measured the freezing point of black liquor coal slurry, witch provide the theoretical basis for making preparing and combustion rational technologies of black liquor coal slurry.