The microstructure and memory property evolutions of as-cast Fe-18Mn-5.5Si-9.5Cr-4Ni alloy with annealing temperature were investigated using OM, ferrite measuring instrument and bending method. The results showed that when the as-cast Fe-18Mn-5.5Si-9.5Cr-4Ni alloy was annealed between 773 and 1173 K, its shape memory effect (SME) was further improved. A high recovery strain of 6.4% was obtained only through annealing the as-cast alloy at 973 K for 30 min, which is 1.2% higher than that of the conventional Fe-14Mn-5Si-8Cr-4Ni alloy after four times thermo-mechanical training. When the as-cast Fe-18Mn-5.5Si-9.5Cr-4Ni alloy was annealed below 1173 K for 30 min, the morphology of δ ferrite phase was still lathy and it could make the stress-induced ε martensite form in a domain manner during deformation, which is the reason why the good SME was obtained in the as-cast alloy annealed below 1173 K for 30 min. When the annealing temperature was above 1273 K, the δ ferrite phase would dissolve in the austenite and its amount decreased. When the annealing temperature was further increased to 1423 K, the amount of δ ferrite phase remarkably increased and its morphology evolved into the island from the lath. The austenite grains could not be well subdivided into smaller domains due to the decrease of lathy δ ferrite phase or the formation of island δ ferrite phase. The SME of this as-cast alloy dramatically decreased when annealed above 1273 K.