Abstract: “Jinmai No. 8” wheat seedlings were exposed to He-Ne laser irradiation (5 mMW·mm^-2) and enhanced UV-B radiation (10.08 kJ·m^-2·d^-1) and the effect on the activities of three polyphenol metabolism enzymes (phenylalanine ammonialyase, polyphenol oxidase and peroxidase) in wheat seedling analyzed. The results show that UV-B radiation enhances wheat seedling phenylalanine ammonialyase activity while it limits activities of polyphenol oxidase and peroxidase. The activities among phenylalanine ammonialyase, polyphenol oxidase and peroxidase in different treatment groups get related with treatment time increased. The long-term enhanced UV-B radiation reduces polyphenol metabolic rate, breaking up biomembranes as free radicals accumulate with time. Damage to wheat seedlings induced by the enhanced UV-B radiation on polyphenol metabolism is limited by He-Ne laser irradiation.