Radiation-induced copolymerizations of various monomers, including perfluoro-olefines with CF2O and of α-olefines with monochlorotrifluoro-ethylene, have been studied. It was found that CF2O can be copolymerized randomly via radical process, with most of monomers examined and that alternating copolymers can be obtained from the copolymerization of a-olefines with monochlorotrifluoroethylene. The structural study of these copolymers was carried out by infrared, X-ray diffraction and NMR measurements. The structure of isobutylene-monochlorotrifluoroethylene copolymer was determined precisely through proton and fluorine resonances.