Abstract: In this paper,Used 1a seeding of Michelia gioi from Qipo forest farm of Guangxi as the research material,the effects of different light intensities on plant growth and development were studied. The results showed that the maximum photosynthetic rate of photosynthetic rate was 8.12 μmol/（m²·s）,and the leaf superoxide（SOD） and catalase activity（CAT） were the highest in four light gradients. With the decrease of light intensity,the physiological and biochemical indexes of Michelia gioi decreased and the growth and functional structure of seedlings were inhibited. Therefore,it can be concluded that during the cultivation and breeding process,the appropriate light can improve the growth and development of nursery stock and enhance the yield and quality of firewood seedling.

Key words: Michelia gioi, shading stress, growth index, photosynthesis, physiology and biochemistry