Olfactory threshold was examined in 33 patients who had been received total laryngectomy, using T & T Olfactometer with the vapour of Iso-valeric acid and Skatol. Also Aronamine F test was under-gone in 33 patients. The results were as follews : 1) Eleven of 13 cases who had esophageal voice and 10 of 20 cases who had no esophageal voice could smell in their daily lives(p<0.05). 2) In each vapour of Iso-valeric acid and Skatol, the statistical significance was observed between sniffing method and injection method according to T & T olfactometry(p<0.05). The recognition threshold in injection method was lower than that in sniffing method. 3) Regardless of vapour(Iso-valeric acid & Skatol) or method, the statistical significance was observed between speaker group and non-speaker group(p<0.05). 4) There was no correlation between age and recognition in used vapour and method according to T & T olfactometry. 5) There was correlation between Iso-valeric acid and Skatol in sniffing method but no correlation in injection method during postoperative period. Postoperative recognition threshold by sniffing method for the vapour of Iso-valeric acid and skatol in esophageal speaker group showed a decreasing tendency of as follow-up period(p<0.05). 6) In total laryngectomized patient, all cases showed no response in Aronamine F test. The mechanism of Aronamine F test was confirmed by blocking the air stream coming into the nasal cavity from stoma. Namely, the smell of vapour injected into the antecubital vein is felt arriving at olfactory fissure through choana expelled from alveoli. Therefore, esophageal speech should be skillfully executed to maintain olfaction of total laryngectomized patients. The result of Aronamine F test was compatible with the theory of venous olfaction.