Rhinomanometry was the most reliable method to evaluate the degree of nasal obstruction objectively. Total nasal resistance was studied with active anterior rhinomanometry in 64 healthy persons and 95 subjects who complained of nasal obstruction. 34 patients who underwent a nasal surgery for nasal obstruction were examined preoperatively and postoperatively with active anterior rhinomanometry and the patient's subjective assessment of nasal obstruction. The results were as follows ; 1) The mean total nasal resistance was 3.89 cm H20/LPS(SD±1.79) in normal controls and the mean total nasal resistance was 6.64 cm H20/LPS(SD±2.94) in patients group. 2) A high degree of correlation was found between the total nasal resistance and the patient's subjective assessment of nasal obstruction(r=0.61, p<0.01). 3) The mean total nasal resistance after surgical group was 6.96 cm H20/LPS before surgery and 4.15 cm H20/LPS after surgery. 4) The total nasal resistance after surgery in patients whose symptom of nasal obstruction was improved was reduced, but the total nasal resistance after in patients whose symptom of nasal obstruction was not improved was slightly increased. 5) The total nasal resistance before surgery in patients whose symptom of nasal obstruction was not improved was within normal range of the total nasal resistance.