Martensitic transformation and effects of thermal fatigue cycles on the transfer mation temperature and shape recovery of Ti-Ni-Cu alloys were investigated by means of electrical resistance measurement, thermal fatigue tests and transmission electron micros copy. Thermo-mechanical treatment at 600℃ for one hour after cold rolling showed the best shape recovery effect irrespective of Cu concentration. Substitution of a small amount of Cu for Ni in the equiatomic composition of Ti-Ni showed folling results ; Ms-temperature of the Ti-Ni-Cu alloy increased slightly with the increase of Cu content, The range of transformation temperature for Ti_(50)Ni_(40)Cu_(10) alloy(i.e., T_(Mf-Af)) was reduced to 7℃. After stress relief treatment at 750 ℃ for one hour, the Ti_(50)Ni_(45)Cu_5 alloy showed good two-way memory effect. Change of the M_s temperature was observed to a certain number of thermal cycles, and it became nearly constant after a critical number of thermal fatigue cycles.