Abstract: With the assistance of osoilloscopic impact technique,dynamic bending yield strength σ_yd and maximum behding yield strengih σ_max were derived by the graphit method on the basis of loading-displacement curve,and then cleavage fracture stress σ_f was obtained accordingly. The test result showed that the ratio of dynamic strength and static strength is 1.25~1.30,by which the value of low temperature tensile strength of material could be evaluated.