Thermoplastic polyurethanes (TPUs) with unique properties such as elasticity, flexibility, mechanical strength have been applied for a wide variety of application. In general, TPUs comprise two segments in which diisocyanate and diol generate the hard segment (HS) whereas polyol generates the soft segment (SS). In this study, a series of TPUs have been synthesized employing hexamethylene diisocyanate as a HS, 1,4-butanediol as a chain extender, and polycaprolactone (PCL, MW ≈ 500–2000) diol as SSs. The producing TPUs were characterized by infrared and nuclear magnetic resonant spectroscopy, and gel permeation chromatography. The mechanical properties of the resultant TPUs were investigated by universal testing machine, thermogravimetric analysis, and differential scanning calorimetry. The influence of the HS/SS ratio and the MW of the PCL on the properties of the TPUs was also investigated. The resultant TPUs exhibit high tensile stress up to 65 MPa and breaking strain up to 990%.