<p>The effect of liquid crystallinity on the rheological properties of ethylcellulose solutions in the isotropic phase has been examined using four solvents. Double-logarithmic plots of dynamic viscoelasticity at different temperatures can be superposed with each other by the combination of arbitrary horizontal and vertical shifts. However, it has been found that some plots are superposed in the framework of the conventional time-temperature superposition principle and the other needs further shifts. Accordingly, it is asserted that the isotropic phase consists of two categories and what should be called semi-isotropic phase lies between full-isotropic and liquid crystal phases. The conditions for respective phases with respect to the ethylcellulose concentration and temperature have been mapped out as a consequence of rheological analysis. The feature of the semi-isotropic phase is pictured by the local alignment of ethylcellulose chains precedent to the formation of a cholesteric liquid crystal, which would contribute to the reduction of chain entanglement. The zero-shear viscosity as well as the plateau modulus in the full-isotropic phase can be scaled by the concentration with an exponent that is independent of the solvent, while at the same time it is revealed that ethylcellulose chains exhibit specific interaction with each solvent. The rheological behavior of full-isotropic concentrated solutions can be characterized by that of semiflexible chains in the tightly-entangled regime.</p> Graphical Abstract <p></p>