A series of (Fe50Ni50)Cu1-x granular films were prepared using magnetron controlled sputtering method. The magnetic-transport and microstructure of FeNi-Cu films deposited at room temperature and then annealed at various temperatures were investigated through TEM, XRD and conventional four probes method under room temperature, respectively. The giant magnetoresistence (GMR) as a function of FeNi volume fraction for as-deposited FeNi-Cu films reached a maximum of about 1.8% at the volume fraction of 32%. With increasing the annealing temperature, the GMR of films with the volume fraction less than 26% reaches a peak at certain annealing temperature. While for films with the volume fraction larger than 26%, the GMR have almost no changes at first and then decrease with increasing the annealing temperature. In addition, the relationship between magneto-transport and the microstructure, morphology of granular films is discussed.