Several investigators suggested that appreciable numbers of subjects with allergic rhinitis demonstrated increased bronchial responsiveness to a cholinergic agent. It is uncertain that allergic rhinitis and atopic bronchial asthma are individual disease or sequential process from allergic rhinitis to bronchial asthma. To evaluate the relationship between allergic responses and bronchial responsiveness to methacholine in allergic rhinitis patients, we studied allergy skin test, RAST, total IgE level, total eosinophil count and methacholine bronchial challenge test(Chai et al, 1975) in 48 allergic rhinitis patients. Of them, group I showed bronchial hyperresponsiveness to methacholine(47.9%) and group II showed negative response(52.1%). The methacholine PC₂₀ level of 19% of all patients was less than asthmatic range(4.66mg/ml). Most patients showed positive response(>2+) to house dust mite on allergic skin prick test. The skin reactivity to Dermatophagoides farinae(D.farinae) was not significantly different between two groups. The positive rate of RAST value on D.farinae(>class 2) was significantly higher in group I patients(p<0.05). No association was found between lower respiratory symptoms and smoking status and bronchial responsiveness to methacholine. There was no significant difference in total IgE level and total eosinophil count between two groups. It is suggested that serum specific IgE level to causative allergen might contribute to develop bronchial hyperresponsiveness in allergic rhinitis patients.