The result shows that the wheat seedling has partly ability of excision repair, and the time of repair peak is about from four to six hours after the UV-B radiation. By excision repair pathway, the repair for the removal of damage induced by UV-B radiation from cellular DNA of the wheat can be influenced by He-Ne laser irradiation. The ability of excision repair of the wheat can be enhanced by He-Ne laser irradiation, and the excision effect of the He-Ne laser irradiation is obviously at the excision peak (at five hours) . The peak of DNA repair synthesis was from six to seven hours after treated by He-Ne laser and UV-B irradiation.