Abstract: The Ti—Ni—Mo shape memory alloy and fixating device for bone fractures using the same are provided, in which a very small amount of Mo of 0.5 at % or 0.7 at % is added Ni for to a Ti—Ni alloy, in order to maintain a transformation temperature whose martensite transformation start temperature (Rs) is 4-35° C. and whose inverse transformation finish temperature (Af) is 6-37° C. to be consistent, so that the transformation temperature can be applied to the human body most ideally, and enhance a corrosion resistivity. The Ti—Ni—Mo shape memory alloy is preferably made of Ti of 48-52 at %, Ni of 48-52 at % and Mo of 0.1-2.0 at %, in a composition ratio.