A series of polycarbonate-based shape memory polyurethane elastomers were synthesized by one-step melting method using carbodiimide-modified MDI (MM103), 1,4-butanediol (BDO) and polycarbonate 1,6-hexanediol esterdiol (PCDL). The effects of hard segment content on the properties of the material were investigated by FT-IR, differential scanning calorimetry, hardness test, tensile strength test, water absorption test and shape memory test. The results show that with increase of the hard segment content, the hardness increases gradually, and the water absorption, tensile strength and elongation at break increase at first and then decrease. When the hard segment content is 15%～20%, the shape fixation rate and shape recovery rate of (polycarbonate-based shape memory polyurethane) PCPU are the highest.