In order to understand the ultrastructure of the tectorial membrane(TM) in avian inner ear and the relations between TM and hair cells and supporting cells, scanning electron microscope(SEM) and transmission electron microscope (TEM) were used to observe the ultrastructure of TM in chick inner ear. The results were that: when viewed under SEM, TM, which possessed a lot of holes inside, was triangular in shape in cross-section and the surface of TM presented fibrous net; when viewed under TEM, TM consisted of fine fibrils and gelatinous substance, only the tallest row of stereocilia and the kinocilium in each hair cell were inserted to TM. The microvilli of supporting cells were anchored to TM by cotton-like fibrous webs. This junction had both elastic and firm, to a certain extent, this kind of junction restricted the movement of TM. According to these structures, there should be different patterns of response to sound stimuli between avian cochlea and mammalian cochlea.