The rheological properties of high concentrated wood pulp cellulose 1-allyl-3-methy-limidazolium Chloride ([Amim]Cl) solutions were investigated by using steady shear and dynamic viscoelastic measurement in a large range of concentrations (1025 wt %). The measurement reveals that cellulose may slightly degrade at 110 degrees C in [Amim]Cl and the CoxMerz rule is valid for 10 wt % cellulose solution. All of the cellulose solutions showed a shear thinning behavior over the shear rate at temperature from 80 to 120 degrees C. The zero shear viscosity (?o) was obtained by using the simplified Cross model to fit experimental data. The ?o values were used for detailed viscosity-concentration and activation energy analysis. The exponent in the viscosity-concentration power law was found to be 3.63 at 80 degrees C, which is comparable with cellulose dissolved in other solvents, and to be 5.14 at 120 degrees C. The activation energy of the cellulose solution dropped from 70.41 to 30.54 kJ/mol with an increase of concentration from 10 to 25 wt %. The effects of temperature and concentration on the storage modulus (G'), the loss modulus (G) and the first normal stress difference (N1) were also analyzed in this study. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012