Abstract: With the quasi-static compression property as reference, the dynamic mechanical property of 03 Cr21 Ni14 Mn5 Mo3 N stainless steel was studied in the high strain rate at two temperatures of 20℃ and-40℃ through the Johnson-Cook pressure bar test in the form of air gun. On the basis of Johnson-Cook model, the constitutive relation of 03 Cr21 Ni14 Mn5 Mo3 N stainless steel was established. The results showed that the strength of the 03 Cr21 Ni14 Mn5 Mo3 N stainless steel in the two conditions of quasi-static and high strain rate went up with the declining of the temperature. Different from the quasi-static, the 03 Cr21 Ni14 Mn5 Mo3 N stainless steel represented the obvious hardening effect with high strain rate. The dynamic strength improved when the strain rate rose from 1 500/s to 4 000/s, but the improvement of hardening effect was not obvious.