Poly(ethylene terephthalate)(PET) and nylon 6 films stretched uniaxially and biaxially were sputter etched in the presence of argon gas. The surface of the etched films was investigated using a scanning electron microscope(SEM). While cracks perpendicular to the stretched direction were observed in the uniaxil stretched films sputter etched for 30 min., many protrusions were formed in the biaxial stretched films at the height of 0.3-0.4 gm for PET and $0.1-0.2mum$ for nylon 6. The tops of two or three protrusions merged etching time increased to 60 min. The contact angle to water of the sputter etched PET and nylon 6 films decreased steeply when etched for one to 3 min. In order to investigate chemical changes on the surface ESCA analysis was carried out. In both films sputter etched $C_{1s}$ intensity decreased and $O_{1s}$ intensity increased compared with the unetched ones.