Bainite transitory formation, during the heating of a martensitic copper base SMA, was predicted by DSC and DTA and confirmed by XRD, OM and TEM only in hot pressed air cooled state homogenized and tempered at 573 K. In this heat treatment state, due to the pre-existence of α-phase, bainite amount is expected to be too low, therefore nondistinguishable, for higher tempering temperatures, where it is suggested that transitory α 1 bainite turned to equilibrium α-phase. The results suggest that bainite formation could be considered as a precursor of α-phase during the heating of Cu-Zn-Al martensitic alloys, with no pre-existing α.