Focusing on the alpha' --> gamma reverse transformation in pre-deformed 1Cr18Ni9Ti stainless steel, the present paper represents the different stages of the reverse process controlled respectively by nucleation-growth and shear transformation mechanisms. Thermal analyses combined with ferromagnetic measurements were used to investigate the whole process and to give their temperature ranges. It was found that the degree of deformation might take roles in the acting of the reverse mechanism, and the shear type transformation can benefit from the increase of reduction. For 90% prior deformation, the nucleation-growth reverse transformation began at about 583 K, while the shear transformation occurred between 763 and 883 K. The obtained structure underwent significantly recovery and recrystallization at 923 K. Part of the austenite obtained by shear-type reverse transformation would transform back again on cooling to room temperature in annealing. And an unusually reversible behavior during cyclic thermal process was detected. Ferromagnetic analysis and TEM observation showed that this reversible behavior could be damaged during the process of recovery and recrystallization.