Nasal obstruction is one of the most popular symptoms caused by the diseases of nose and paranasal sinus. We use rhinomanometry （RM） and acoustic rhinometry （AR） to evaluate the nasal patency objectively. RM is a physiological examination indicating the nasal resistance as an index of nasal patency. On other hand, AR is a morphological examination which could measure the cross-sectional area of nasal cavity. As unilateral nasal patency spontaneously changes in human beings, often referred to as‘ nasal cycle’, single measurement not seldom has insufficient reliability. Therefore, several measurements often are necessary to increase the accuracy of the examinations.