The hydrodynamic performance of aqueous dextran solutions, including the rheological and thixotropic properties, were investigated. Three kinds of dextrans with different molecular weights were employed to examine the effects of the molecular weight, concentration, temperature, and so forth on the hydrodynamic properties of aqueous dextrin solutions. The results showed that an aqueous solution of a dextran with a high molecular weight of 5.223 x 10(5) at a high concentration of 30 wt % had pseudoplastic properties, in contrast to the conclusions of other researchers finding that aqueous dextran solutions were Newtonian liquids. The viscosity of the aqueous dextran solutions decreased with temperature, and the activation energy was calculated to be 16,849.2 J/mol with a 70 wt % dextrin (weight-average molecular weight = 5.223 x 105) solution. (c) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 1523-1529, 2009