An attempt was made to explain the reason why the temperoture and humidity of the inspired air in the nasal cavity rise, by applying the theory of alternating contact between water and air.From these considerations it was concluded that the heat and the humidity of the air in the nasal cavity rise pattly due to the moisture of the exspired air remaining in the nasal cavity and mostly due to vapor emitted at the inferior tubinate caused by the decleine of the relatuie humidity of the inspired air due to heating the air at nostril.It also facilitates the rise in temperature and hummidity in a very short time.Moreover, my calculation on the varions accascons proved that the postine and negative presure formation in the nasal cavity held in breathing helps the formation of the respired air stream in it, and has no connection with the heating and the humidification of the inspired air.