Abstract: The high temperature flow behavior of 23Cr-12Ni steel was studied through GLEEBLE 3500 thermomechanical simulator at 1000℃to 1250℃and strain rate of 0.001 to 10s^-1.By computing the strain-hardening θ,under various deformation situations,the critical stressσ_c and critical strain ε_c were ascertained,and the correlation between critical values and peak values was discovered.The results show that:the critical conditions for onset of dynamic recrystallization is:ε＞ε_c=5.06×10^-2Z^0.011;and the relationship between the critical values and peak values of dynamic recrystallization is:σ_c=0.8404σ_p;ε_c=0.088ε_p.