The surface composition and structure of the 3C-SiC(111) surface prepared by thermal reaction of C-60, molecules with the Si(111) substrate are investigated with scanning tunneling microscopy and high-resolution electron energy loss spectroscopy. Three distinct surface reconstructions are observed by STM on the SiC(111) surfaces as the reaction temperature varied from 800 to 1200 degrees C, The (2x2) and (2x3) reconstructions observed under low reaction temperature (<900 degrees C) are considered to be a C cluster-covered surface, The (3x3) structure yielded at the elevated temperature (1100 degrees C) is believed to be the Si-terminated 3C-SiC(111) surface. A transient (4x3) structure shows up at around 1000 degrees C during the annealing processing. The surface composition and reconstruction are further confirmed through the optical Fuchs-Kliewer surface phonon measured bl situ by high-resolution energy loss spectroscopy. The diffusivity of Si atoms through SiC film at various temperatures is suggested as the main reason for the formation of different surface reconstructions.