Abstract: Carbon nanotubes(CNTs)/ZM5 alloy composites were fabricated by stirring casting method with the protection of Ar.High temperature tensile properties of the composites were tested and the fracture sections were observed via SEM.The results show that the CNTs/ZM5 alloy composites has good tensile properties at high temperature.When the tensile rate was 1mm/min,the tensile strength of the composites was up to 117.65 MPa at 473 K,increased by 20% to the as-cast ZM5.While the maximum ductility of the composites was 8.32% at the 05% addition of CNTs,enhanced by 21.62% to the as-cast ZM5.And the fracture mode of the composites mainly consisted of dimples and tear edges at the elevated temperature.