The UV transmission curves of high molecular films wereaffected by γ-irradiation.(i) At dose of 1×106 R, no significant effects no filmswere observed.At dose of 7×106 R, the UV transmissioncurves of pure cellophane, polyvinylalcohol, polyethylene, polypropylene, polyvinyl chloride and polycarbonate changedtheir shapes and patterns, whereas those of polystyrene andpolyester remained unchanged. (Fig.1-7)(ii) Byγirradiation, some of the films browned, andmoreover, the tints of color gradually changed with thelapse of time after irradiation.The UV transmission curves of polvvinvlidene-chlorideand polyvinyl chloride, irradiated at the dose of 4.5×106 R, were shifted slowly downwards, indicating further decomposition. (Fig. 8, 9) On the contrary, the UV curve of irradiated polycarbonatewas shifted downwards for a time, and then upwards, indicating restoration of chemical status of the films.(iii) At the dose of 1×107 R, the progressive changesin the UV curves of polyvinylidene chloride (Fig. 12) andpolycarbonate (Fig. 13) were more remarkable.The UV curves of irradiated and colored glass plates, probably containing free radicals, also were shiftedupwards during storage. (Fig. 14)