In this experiment, the influence of various H1-antihistamines on the contractile action of norepinephrine was studied in mucosal strip of human inferior turbinate. The results were as follows : 1) Histamine, norepinephrine and tyramine elicited the contractile response of mucosal strip of human inferior turbinate in dose dependent manner. 2) Contractile action of histamine was significantly inhibited by chlorpheniramine, methdilazine, chlorcyclizine or diphenhydramine, respectively. 3) Contractile response of mucosal strip of human inferior turbinate to norepinephrine was potentiated by chlorpheniramine and diphenhydramine but attenuated by chlorcyclizine and methdilazine. 4) Contractile response of mucosal strip of human inferior turbinate to tyramine was inhibited by chlorpheniramine, diphenhydramine, chlorcyclizine and methdilazine. From these result, it is suggested that some kinds of H1-antihistamines can modify the action of monoamines. More over it is inferred that the potentiation of contractile response of isolated mucosal strip of human inferior turbinate to norepinephrine by chlorpheniramine or diphenhydramine was due to inhibition of amine pump uptake mechanism at sympathetic nerve terminal.