Abstract:Gametophytic development of Sinephropteris delavayi(Franch.) Mickel in Brittonia was first studied by the microscope. The spores germinate at about 6 days after cultured. The germ filiaments developments are uniseriate and can forked into 2~3 branches. The meristem of prothallial is unconspicuous. Mature prothallu are approximately cordate. We also discussed the characteristic of meristem, hair and sexual organs so that can show the reasonable view of Mickel who divided into an unique genus S.delavayi.