Sodium octylbenzenesulfonate (SOBS) and sodium dodecylbenzenesulfonate (SDBS) were added to the polypropylene (PP) melt, and several PP films with different quantities of these additives were prepared by a melt press method. The storage viscosity (η'), storage modulus (G'), and loss modulus (G") were measured in a temperature range of 170∼195℃ on an oscillating rheometer. No differences between the modified Cole-Cole plots (log-log plot of G" against G') for the PP containing additives and that for the pure PP were found in the whole temperature range. However, it was recognized that in a wide shear rate region, both the η' and G' of the PP containing SOBS increased as the content of SOBS exceeded ca.8 wt%. This fact was explained as an aggregation effect of the additives in the PP substrate, while the point of view was supported by differential scanning calorimetric and scanning electron microscopic observations for the films of the PP containing SOBS and SDBS. The filament was spun successfully from the polymer melt with the content of SDBS less than 8 wt%, but fracture of the filament occasionally occurred during the drawing of the one with more than 3 wt% SDBS content. Finally, the hot water fastness property of the SDBS in the PP substrate was examined by a visible spectroscopy on the basis of the ionic bond formation behavior between SDBS and C. I. Basic blue 41.