The changes in the cell surface morphological stracture are observed ander a scanning electron microscope during carly embryomic development in Bufo raddei Stramch. The cells at the blastopore of the gastrufa first change their shape, invaginating and leagaing. The changes in cell sarface structure become the most promiment during menrala (stages 13-16). whem the cell surface turns from circular into clear-deamreated polygomal, the cell boandaries become samewhat, protaded, looking like crests, and the ectoderm begins to differentiate into aeural ectoderua and epiderntal ectodern. The cells in the neural ectoderm have microvilli on the sarface. There are two maia typs of epidernal cels in the ectodrm. the ciliated and non-cilated which have shallow depvessions, microvilli-like projections and secretory graules on the sarfae. The first cilila appear daring the imitial phase of the mearal plate (stage 13). They greatly increase both in menber and in leagth during the growth of the tail bud (stages 19-22). and begin to regress partly during the opercmlam fold (stages 23-25).