The microstructure and magnetic domain structures of the annealed quick-quenched ribbon Sm2Fe14.5Cu0.5Ca2Cx were studied by using magnetic force microscope. The results of the topography image and magnetic force image (MFI) show that the grain size is between 2555nm, whereas the domain size is between 200400nm. The magnetic domain length scale is much larger than the grain size. The domain comprises of a lot of grains, which were called interaction domain. The detail analysis such as power spectral density analysis, the maximum phase shift and roughness analyses on the MFI demonstrated that they are connected with the intrinsic magnetic properties such as HA in some way.