When the air flow fails to pass through the nose, the anatomical alteration of nasal of mucosa occurs and this change has been documented especially on respiratory epithelium. But the morphological data to the fate of the olfactory epithelium subsequent to laryngectomy in human or experimental animals cannot be found in the literature. Experimental study was thereafter undertaken to observe the morphological changes of olfactory epithelium in laryngectomized dogs by the transmission and scanning electron microscopy and to investigate the possibility for olfactory rehabilitation. The results were followed : 1) The morphological changes of the olfactory epithelium one week after the laryngectomy were the vesicular swelling and the ciliary shortening or losing. 2) The regenerative evidence of the olfactory epithelium such as the mixed appearance of young- and adult- type olfactory vesicles, the microvilliary elongation of supporting cells was noticed in dogs 9 to 17 weeks after the laryngectomy. 3) 28 weeks after the operation, olfactory vesicles showed the developing patterns of all five stages which were able to observe in the normal olfactory epithelium. However, the adult-type olfactory vesicles were appeared to be shrunken a little bit, suggesting the incomplete regeneration at this time. In conclusion, decrease of olfactory acuity in laryngectomized subjects suggested to be somewhat related with the morphological alteration of olfactory epithelium. Concerning to reactive neurogenic potentiality of the olfactory epithelium, recreation of the air flow with odorous stimulants would contribute to complete regeneration of the olfactory epithelium.