Fibers and films of both p- and m-aramid fibers and films were treated with sputter-etching in the presence of argon. Surface of the treated films was investigated using scanning electron microscope (SEM) and electron spectroscopy for chemical analysis (ESCA). Many protrusions were produced on the surface of both films by the sputter-etching. In the case of p-aramid film, protrusions were grown in height with etching time. Then the top portions became large by coupling themselves after the long treatment for 20min. m-Aramid film also showed protrusions, but they were relatively smaller than those of p-aramid film. Contact angle to water of the sputter-etched films decreased rapidly at the initial treatment, while the critical surface tension increased drasticaly. ESCA analysis was carried out to elucidate the chemical changes on the film surfaces. The O_1S/C_1S ratio of the p-aramid film was increased obviously with the treatment of sputter-etching. This indicates the oxygen uptake in the etched surface, showing the simultaneous action of chemical modification induced by sputter-etching.