The harmonics of a free electron laser (FEL) were irradiated in vacuum to surfaces of compressed C 60 and a mixture of C 60 and I 2 . The power and frequency of the fundamental FEL macro-pulse were ca. 0.5mJ/pulse and 2Hz, respectively. The irradiation time was 120–180min. After irradiation of FEL with a typical wavelength of 450 or 345nm, the Raman peak of Ag(2)-derived vibration mode of C 60 shifted to the lower-energy side. The Raman peak shift of the mixture powder sample was greater than that of pure C 60 . Furthermore, changes of the crystalline structure indicated that various intermolecular combinations occurred by irradiation. These results strongly suggest that three-dimensional polymerization of C 60 was promoted by laser irradiation and the effect of photon-assisted hole-doping from iodine atoms to C 60 molecules.