Abstract: Shape memory effect （SME） measurements of specimens under thermo-mechanical cycling （“training”） with different strains and recovery temperatures in an Fe-33.7（wt）%Mn-55.22（wt）%Si alloy had been conducted. It was found by electron microscopic analysis that all the stress-induced martensite is with lamella structure. Large strain or incomplete recovery in training causing the multiplication of dislocation distroy such structure, result in impairment of the crystallographical reversibility and in turn, reduce the SME.