Effect of aging on successive martensitic transformation in a Ti–47 at%Pd shape memory alloy has been studied by means of differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). After short time aging successive transformation takes place in Ti–47 at%Pd alloy irrespective of aging temperature. On the other hand, after relatively prolonged period only the specimen aged above 1073 K shows successive transformation. The change of transformation behavior with aging condition is discussed on the basis of equilibrium between TiPd matrix and Ti₂Pd precipitate. The homogeneity range of TiPd compound is also estimated from the transformation behavior and TEM observations.