TiNiCu films with different Cu contents were prepared by co-sputtering of TiNi and Cu targets using a magnetron sputtering system. Film microstructure, phase transformation behavior and crystallized structures were characterized. The substitution of Ni by Cu in TiNi based films resulted in a dramatic change in martensite structure and film orientation. With the increase of Cu content in the films, both the transformation temperatures and hysteresis decreases significantly from both differential scanning calorimeter (DSC) and X-ray diffraction (XRD) results. However, from both DSC and curvature measurement results, the specific heat and the maximum recovery stress generated during martensite transformation decreases.