In this work, the effects of changing molecular weight of polyol (2000, 3000, and 4000) and block ratio as well as deformation amplitude on thermal, structural, and shape memory properties of polyester urethanes based on diphenylmethane diisocyanate, polycaprolactone diol, and 1,4-butanediol were investigated. Fourier transform infrared spectroscopy was used to check the accomplishment of the polyurethanes synthesis. Thermal, structural, and shape memory properties of synthesized SMPUs were measured using differential scanning calorimetry, wide angle X-ray diffraction, and tensile cyclic tests, respectively. It was found that as the crystallinity of soft segments increased, the ability of the samples in fixation of temporary shape was higher. On the other hand, the shape recovery was dominated by the hard segment content and there was a minimum critical HSC for the samples to show appropriate shape memory effects.