On 37 patients with nasal allergy and 37 non-smoking healthy volunteers, maximal expiratory flow-volume curve and volume-time curve were obtained. To find the characteristic flow changes, the flow curves were classified into five patterns from type A to type E. The results showed that the incidence of type A was significantly lower in patients with nasal allergy than in the control group, while the rate of type E was significantly higher at 46% and the rate of type B was particularly high (32.4%) in the patient group. It was demonstrated that 77% of the subjects provided B or C flow-volume curves, while those with pale nasal mucous membranes developed D and E formats. In patients with nasal allergy, these patterns are useful in diagnosing remarkable differences in the lower airways.