The photo oxidation of cis 1

4 polybutadiene in the presence of C60 was studied by pursuing the IR spectra changes with irradiation time and determination of the peroxide with spectrometric method.It was found that C60 acted as a effective photosensitizer to convert the molecular oxygen into singlet oxygen and thus the ene reaction of singlet oxygen with carbon carbon double bonds in the polymer chain took place.The content of peroxide formed increased with the increase of the irradiation time and the concentration of C60

but seemed to have little relation with the concentration of cis-1

4-polybutadiene under current experimental conditions.Isomerization of double bonds with little carbony group formation were also observed during the photo-oxidation.