<正>The intrinsic viscosity [77], Muggins constant （KH）, [η]0,α3 and flow activation energy values of nylon 6 have been measured in water/m-cresol （0/100-20/80） systems at different temperatures （20-60癈）. It has been found that the intrinsic viscosity, [η]0 andα3 increase with the increase in water contents in m-cresol up to 15% and then decrease. They increase with the increase in temperature irrespective of solvent composition. It has been noted that the percent increase ofα3 is the highest at 60℃and the lowest at 20℃for a particular solvent system. The intrinsic viscosity data obey Arrhenius equation over the considered conditions. The activation energy and the KH values decrease very sharply with the addition of water, giving a minimum value at 15% of water and then increase slowly. The variation of all the parameters has been explained in terms of variation in thermodynamic quality of solvent with the addition of water to m-cresol and change in temperature, resulting in the change of conformational and orientational properties of polymer molecules. This change of solvent quality also results in variation of selective sorption of solvent over the polymer, such as hydrogen bonding, etc.