The hot deformation behavior of pre-deformation Mo-0.3La alloy was studied on the Gleeble-3500 thermal-mechanical simulator at 973～1273K with the rate of deformation 0.001～0.1 s-1 and the true strain of 60%, and the constitutive equation was established by hyperbolic sine model with Zene-Hollomon parameter. The results show that in this experimental conditions, the dynamic recrystallization characteristics of the true stress-strain curves are observed. Pre-deformation Mo-0.3La alloy, at high strain rate 0.1 s?1 or low temperature 973K exhibits workhardening, dynamic recrystallization is significant at low strain rates (0.001 and 0.005s-1) of 1273K. The high angle grain boundaries of the pre-deformation alloy is 31.65%. After redeformation, the high grain boundary decreases to 17.14%, and there are a small amount of recrystallized grains(6.08%), with the increase of deformation temperature, high grain boundaries and recrystallized grains increase. Calculated by the constitutive equation, the deformation activation energy Q is 287.08 kJ/mol, and the stress exponent n is 14.40. Using this equation, the average relative error between the theoretical calculations and experimental results is only 3.25%.