Nasal obstruction is generally correlated well with increased nasal resistance. Effective therapy for nasal obstruction depends on accurate diagnosis. Rhinomanometry is an objective method for documenting nasal obstruction and assessing therapeutic intervention. Previously the authors have reported nasal airway resistance with 70 healthy persons measured by both anterior and posterior methods. Now, we measured the nasal resistance with the mask technique of active anterior rhinomanometry in 46 patients who underwent nasal surgeries for nasal obstruction and then we analyzed the data. The following results were obtained : 1) The mean total nasal resistance was 1.551±0.774 cmH₂O/LPS in control group and 1.998±0.938 cmH₂O/LPS in patient group(p<0.005). 2) After decongestion, the total nasal resistance of patient group was decreased. 3) A high degree of correlation was found between the total nasal resistance before surgery and the subjective assessment of nasal obstruction. 4) There was no significant correlation between the preoperative total nasal resistance and the objective findings of nasal cavity. 5) The total nasal resistance was meaningfully decreased after the nasal surgery ; 1.998±0.938 cmH₂O/LPS before surgery and 1.121±0.445 cmH₂O/LPS after surgery(p<0.005). 6) There was a significant correlation between the degree of improvement of nasal obstruction and the difference of total nasal resistance before and after the nasal surgery. 7) The difference between preoperative and postoperative total nasal resistance tended to be prominent in the cases of severe subjective nasal obstruction before surgery.