The elastomers with different hard segment structure were synthesized by one-step method, using azido copolyethers of 3,3-bis(azidomethyl) oxetane (BAMO) and tetrahydrofuran (THF) as soft segment and different diisocyanate and chain extender as hard segment. The structure was characterized by WAXD and the results show the diffraction peak intensity of elastomer using rigid chain extender (SR) is higher than that of elastomer using flexible chain extender (DEG), which means that the hard segment is ordered in this elastomer. The mechanical properties at different temperature were tested by room temperature tensile, high temperature creep and low temperature dynamic mechanical testing analysis. The results show that the room tensile strength of elastomer gets to 5.36 MPa in SR chain extender, compared to 2.29 MPa in DEG chain extender. The initial decomposition temperature of former reaches to 208 ℃ higher than the latter 198 ℃. The high temperature creep decreases from 90.1% to 39.7%. The mechanical property in symmetric structure of toluene diisocyanate (TDI) is higher than that of 4,4′-diphenylmethane diisocyanate (MDI) cured elastomers. Except the room temperature tensile strength, less difference can be seen in low temperature and high temperature mechanical performance, despite TDI or MDI used as curing agent.