The surface structures of three kinds of poly(ethylene oxide)-segmented nylon (PEO-Ny) molten films were investigated using a scanning electron microscopy (SEM), an electron spectroscopy for a chemical analysis (ESCA), and a static secondary ion mass spectrometry (SSIMS). The PEG-Ny's used were high semicrystalline PEG-segmented poly(iminosebacoyliminohexamethylene) (PEO-Ny610), low semicrystalline PEG-segmented poly(iminosebacoylimino-m-xylene) (PEO-NyM10), and amorphous PEG-segmented poly(iminoisophthaloyliminomethylene-1,3-cyclohexylenemethylene) (PEO-NyBI). SEM observations show that the surfaces of the PEO-Ny610 and PEO-NyM10 films are composed of spherulite, and that PEO-NyBI film has a smooth surface. The results of ESCA and SSIMS exhibit the significant enrichments of PEO segment at the surfaces of all the films regardless of the crystallinity. The reason for the enrichment of PEG segment was discussed in terms of the surface tension of the corresponding homopolymers in the melting state.