Polycrystalline Ti50Ni5o, Ti45Ni55 , Ti44.8,Ni55.2, Ti49.2Ni5o.8 , Ti44.5Ni55.5 and Ti50.3Ni49.7 of shape memory alloys SMA's have, been prepared successfully. The structure of the ingots was determined by X-ray diffraction patterns. By vacuum thermal evaporation technique, TiNi thin films with thickness (500nm) at a rate of deposition (0.555nm/sec), have been prepared and under different preparation conditions such as substrate temperature, different percentages for (Ti and Ni) in TiNi shape memory alloy thin films. It has been observed that the amorphous structure was observed for Ti50Ni5o, Ti45Ni55 and Ti44.5Ni55.5 films deposited (at substrate temperature = R.T.). Also the deposited Ti44.8Ni55,2j Ti49.2Ni5o.8 and Ti5o.jNi49.7 films (at substrate temperature = 100°C ) have amorphous structure as evidenced by (XIID). The crystalline structure has been reserved for Ti50Ni5o, Ti49.2Ni508 and Ti5o.3Ni49.7films deposited were obtained at substrate, temperature 200'C as determined by (XRD). However, the structure of Ti45Ni55, Ti44.5Ni55.5 and Ti44.8Ni55.2 fillms deposited at substrate temperature 200°C was amorphous. It has been found that annealing the amorphous structures of Ti45Ni55 and Ti50Ni50 films at temperature (Ta=425°C) become crystalline. On the other hand, the (Current-Voltage) measurements of the amorphous Ti5o.3Ni49.7films under vacuum have led to amorphous-crystalline transformation, which confirmed by using (XRD). A very peculiar phenomenon in the (l-V) increasing the applied voltage to a certain value that led to disconnection due to fracturing the films and breaking the substrate glass slides. repeatedly happening many times. Our inter composition, is that increasing the applied voltage crystalline transformation takes place sudden steeply because the transformation is exothcrmal. The specimen and the glass slide breaks due to difference in thermal expansion. Indeed this breaking of the glass slide is an evidence of a critical state of a memory process in the films. The phase transformation of TiNi (SMA), in this study by using the resistivity measurements versus temperature, depends on: 1. The concentration of (Ti and Ni) 2.The substrate temperature. 3. Annealing temperature. Increasing Ni content has an important effect upon desceasing the M, temperature (Martensite start Temperature). Therefore, M, is function of TiNi composition. TiNi (SMA) films exhibit a thermally reversible process between (austenite phase and martensite phase). At low temperatures, when the SMA thin films in the martensite phase heated, they transform into high temperature austenite phase (also , called parent phase) and recovering their initial shape. Through annealing TiNi films to 425"C a reverse transformation occurs through heating and cooling, in comparison with TiNi films that are not annealed.