Cu-C-70 nanocomposite thin film is synthesized via thermal co-evaporation method. The atomic concentration of Cu in the thin film is found to be similar to 4.5 at.% using Rutherford backscattering spectroscopy. Sequential thermal annealing is performed in an inert atmosphere (in presence of Ar) at various temperatures. Surface plasmon resonance (SPR) is spotted at similar to 585 nm for the sample annealed at 300 degrees C and the SPR peak is shifted towards similar to 621 nm for the sample annealed at 400 degrees C. In order to determine the modifications arising in the structure of fullerene C-70 matrix due to annealing, Raman spectroscopy is used. At the highest temperature of 400 degrees C, the high-intensity Raman active modes of fullerene C-70 can still be observed which shows that fullerene C-70 is not completely transformed into amorphous carbon upto this temperature. Transmission electron microscopy is performed to determine the size of particles which is obtained similar to 35 nm for the sample annealed at 400 degrees C. The red shift in SPR wavelength at 400 degrees C is ascribed to the growth of Cu nanoparticles.