Capsaicin, pungent ingredients of red pepper, is known to excite neuropeptide containing primary sensory neurons in first application, but it's repeated applications makes excitation response decreased. It has been known that this local efferent function of capsaicin sensitive sensory neuron results in nasal hyperreactivity. The aim of this study is to evaluate the effecacy of capsaicin on human nasal hyperreactivity with symptoms and signs scoring system. We used histamine and methacholine provocation test to evaluate the duration of inhibitory effect of capsaicin objectively and to evaluate whether capsaicin has an inhibitory effect on sneezing and secretory response. After the application of capsaicin(30mM, 50μl) soaked cotton packing into the nasal cavity, signs and symptoms of 6 patients with nasal hyperreactivity were observed with the use of scoring system until 3 months and were recorded every week. Histamine and methacholine provocation test were also performed every week and then histamine threshold to induce sneezing and the amount of secretion by methacholine provocation test were recorded until 3 months. The results are as follows : 1) The signs and symptoms of 5 cases were much improved, but not improved in one case with inappropriately applied capsaicin because of severe burning sensation. 2) Histamine threshold to provoke sneezing was increased during follow up period and the amount of nasal secretion in methacholine provocation test returned to that of pre-application of capsaicin within 2 weeks in 5 cases. In conclusion, it seems that capsaicin has a longstanding inhibitory effects on the nasal hyperreactivity with only one or two times of application, but no direct inhibitory effect on secretory response. However, the longer follow up periods and more cases will be needed for funther studies.