The surface structures of solvent-cast films with aramid-poly(dimethylsiloxane) (poly(dimethylsiloxane) = PDMS) multiblock copolymers (PASs) that contained 8, 14, 24, 41, and 71 wt % of PDMS were characterized by angular-dependent X-ray photoelectron spectroscopic (XPS) measurements, static secondary ion mass spectrometric (SSIMS) measurements, and transmission electron microscopic (TEM) observations. The results of angular-dependent XPS measurement elucidated that the surface concentration of the PDMS segments was much higher than that in bulk and further increased with a decrease in the sampling depth. In particular, the Si/C ratios that were determined by XPS at a 10 degrees takeoff angle in PAS films that contained more than 24 wt % PDMS were almost the same as that in the PDMS homopolymer. From the results of SSIMS measurement, the outermost surfaces of all of the PAS films were found to be completely covered with a PDMS segment even if the PDMS content was only 8 wt % in bulk. In addition, we visually confirmed the surface enrichment of the PDMS segment by TEM observation. The free surfaces of all PAS films were predominantly covered with a PDMS thin layer, although the microphase-separated structures in bulk were different according to the PDMS content in PAS.