Abstract: The surface energy of segmented polyurethanes(SPU) with different bulk compositions was measured through contact angles and their surface compositions were determinated by ESCA. The results show that these SPUs are the same in surface energy in spite of their different bulk compositions. This phenomenon was explained qualitatively in terms of the enrichment of soft segments on surface and the fact that the ratios of hard segment to soft segment are the same among the SPUs with different bulk compositions. The surface energy values of SPUs are higher than that of PTMGwith infinite molecular weight, perhaps this is due to the existenceof polar groups such as -O-C-NH- on SPUs surfaces.