Disclosed is a shape memory alloy wire subjected to a cold drawing work, which comprises a shape memory alloy in a martensitic phase which assumes an austenitic phase or a martensitic phase through phase transformation temperatures, has a diameter of 60 μm or less, and has a reverse transformation termination temperature of at least 250° C. By using the alloy wire, a composite material having the alloy wire embedded in a resin having a molding temperature as high as 180° C., such as a glass fiber reinforced resin or a carbon fire reinforced resin, without fixing of both wire ends.