Abstract: As an outstanding performance aviation material, the understanding of dynamic behavior of ultrahigh strength steel 30CrMnSiNi2A at high strain rates is of importance in a range of applications. The curves of stress and strain in different strain rates (500~5000s^-1) of 30CrMnSiNi2A steel are obtained with split Hopkinson pressure bar(SHPB) experiments, and the micro-deformation characters were observed by metallography. The results indicate that 30CrMnSiNi2A steel is sensible of strain rate, and dynamic compression leads to shear failure with the angle 45°. The yield stress increases from 1655MPa to 1908MPa with increasing strain-rate (500~5000s^-1). Through metallographic analyses, the failure is found to be dimple intercrystalline fracture under high strain-rate loading. Meanwhile, the material parameters of Johnson-Cook model are determined through the SHPB experiments and quasi-static results.