It was reported that the incidence of allergic rhinitis and asthma decreases with increasing age. Until now, it has been suggested that this may be caused by a decrease in immunological activity with age. However, recent reports suggest that bronchial hyperreactivity in human without any disease decreases with age. Therefore it can be hypothesized that hyperreactive nasal symptoms may decrease with increasing age. The purpose of this study was to clarify if the nonspecific responsiveness of the nasal mucosa decreases with aging by using histamine and methacholine provocation test. 101 normal subjects who had no history of the nasal disease and administration of drugs such as antihistamines, anticholinergics and steroid spray for at least 2 months were selected in order to evaluate the effect of age on nasal reactivity after histamine or methacholine challenge. After histamine provocation sneezing threshold concentration was recorded and the degree of the nasal mucosa swelling was measured by acoustic rhinometry and after methacholine provocation, the weight of nasal secretion was measured. The results were as follows : 1) The lowest histamine concentration to induce sneezing reflex after histamine provocation increased significantly with increasing age(p=0.029). 2) The degree of the nasal mucosa swelling, measured by acoustic rhinometry, at each histamine concentration decreased with increasing age, and it was statistically significant above the histamine conc. of 10²μg/ml(p=0.305 in histamine conc. 10¹μg/ml, p=0.0002 in histamine conc. 10²μg/ml, p=0.0006 in histamine conc. 10³μg/ml, p=0.0003 in histamine conc. 10⁴μg/ml, p=0.0016 in histamine conc. 10⁵μg/ml). 3) The weight of nasal secretion showed a tendency to decrease with aging after methacholine provocation although there was no stastistical significance(p=0.130). These results demonstrated that a normal person had a decrement of nasal reactivity following histamine challenge or methacholine challenge with increasing age. Therefore we hypothesize there may be spontaneous resolution of allergic rhinitis in old age and aggravation of nasal symptoms with decreasing age.