Abstract: To investigate the relationship between the impulse oscillometry method and plethysmogrophy used in measuring airway resistance, Using the two methods to measure the airway resistance and the ventilation data of 158 patients. The varies of resistance such as Rtot, Rocc, Z rs, R5, R20 had a high degree corelation with FEV 1, and so do the corelation among the varies of resistance. The distributions of R5 and Rtot were almost the same, but after the agreement test, there was difference between them. R5 was less than Rtot. R5 could nearly reflect the change of Rtot, but they were not, equal. The application of the impulse oscillometry method to measure the airway resistance should have different positive criteria from that of plethysmogrophy.

Key words: impulse oscillometry, plethysmogrophy, airway resista