Flexible linking of shape memory polyurethane (SMPU) was tried with a long polyethyleneglycol (PEG) spacer (PEG-600 or PEG-1000) longer than the one tested before (PEG-200). The SMPU was composed of MDI, polytetramethyleneglycol (PTMG), 1,4-butanediol (BD), glycerol, and PEG as a spacer. PEG connected the glycerol hydroxyl group of polyurethane chain via MDI as a connecting agent. Significant increase in both maximum stress and strain at break was attained simultaneously, because of the flexible structure of PEG. Especially, it was shown in the stress-strain curve that the PEGlinked SMPU showed similar behavior and superior tensile mechanical properties to natural rubber. Shape recovery of the PEG-linked SMPU went up to 96 %, and shape retention remained low compared to linear one. PEG-1000 was better than PEG-600 in enhancing the overall tensile strength and shape memory of SMPU.