The present study describes the rheological behavior of three types of coal-water slurry in the presence of a dispersant saponin isolated from the fruit of Sapindous Mukorossi. The critical micelle concentrations of the saponin wereas 0.016 and 0.007g/cc through aqueous extraction and chemical extraction processes, respectively. The rheological characteristics of slurry were measured in the function of coal loadings, pH, saponin concentration, and temperature. The zeta potential of the slurry without additive was found to be 120mV which exhibited a decreasing trend with the adoption of additives. The static stability of the slurry could be maintained up to a maximum period of 30days.