Abstract: The seedling of wheat (jinmai8) were exposed to He-Ne laser (5 mW·mm^-2), enhanced UV-B radiation (10.08 kJ·m^-2·d^-1) and the combined treatment of He-Ne laser irradiation and enhanced UV-B radiation. The measurement permeability of chloroplast membrane，chloroplast protein content，Hill reaction activity and ATPase activity of wheat seedlings. Result enunciation: the chloroplast membrane permeability has increased after UV-B radiated wheat seedlings，chloroplast protein content went down, Hill reaction activity and ATPase activity were restrained. The He-Ne laser can make chloroplast membrane permeability fall，chloroplast protein content go up certainly. Hill reaction activity and ATPase activity were also partially activated.These variety explain enhanced UV-B radiation cause damage chloroplast of wheat seedling, but certain the He-Ne laser partially repair UV-B damage the system of photosynthesis on wheat seedling.

Key words: He-Ne laser, UV-B, Wheat, Chloroplast, The system of photosynthesis