The effects of solvent properties on the surface characteristics of solvent-cast cellulose acetate were investigated. The films of cellulose acetate 54.3% of acetyl value were cast from the solutions varying in thermodynamic quality, and the film properties were studied by means of surface tension measurements. In the surface properties such as the surface free energy, consisting of dispersion and polar contrbutions. and the work of adhesion, significant variations were observed and these were correlated to f-values defined as the balance of solubility parameter and the hystersis on the rough surface. To evaluate the degree of surface roughness, a parameter as the measure of coil dimensions in solution, ($frac{1}{2}$-XH)/V1 was used on the assumption that the degree of surface roughness is proportional to the magnitude of the coil dimensions.