Abstract: The effects of different light intensities on spore germination and the growth of gametophyte of Ceratopteris thalictroides(L.) Brongn. were studied. The results showed that the intensity of 2 000~4 000 lx is suitable for spore germination, the optimum point is at 4 000 lx. When the intensity is around 4 000 lx，the spores easily grow into hermaphrodites gametophyte. When the intensity is around 1 000 lx，the spores mostly grow into males gametophyte. It gives evidence for the cultivation of C.thalictroides and the molecule biology study.

Key words: Ceratopteris thalictroides(L.) Brongn., light intensity, germination probability, males gametophyte, hermaphrodites gametophyte