The rheograms of wheat straw soda black liquor in a shear rate range of 10-10(3) s(-1) were investigated by a Physica MCR 100 rheometer. The rheological properties of wheat straw soda black liquor with different solids content were deliberated in 60-100 degrees C temperature range. All samples exhibit shear-thinning properties with the flow behavior index (n) between 0.715 and 0.865. The Arrhenius model was used to explain the influence of temperature on apparent viscosity of soda black liquor. The Arrhenius parameters, eta(o) and E-a are functions of solids content and expressed by the Ostwald-de-Waele model. The empirical model obtained from the study could well depict the combined effect of solid content and temperature within the range of study. It was concluded from the results that temperature along with the solids content had significant effect on the rheological properties of soda black liquor.