Abstract: Objective: To explore the clinical value and specific changes of impulse oscillometry(IOS) in chronic obstructive pulmonary disease(COPD).Methods: The IOS indices of 50 normal cases and 110 cases of COPD were measured and compared with the traditional lung function indices including FEV₁/FVC%,and FEV₁/Pred%.Results: Compared with normal cases,the peripheral resistance and resonant frequency(Fres) of the 110 patients with COPD rose obviously and the central airway resistance rose in some of them,but the peripheral reactance descended significantly at the same time(P<0.05).There were characteristic changes of IOS in COPD.Conclusions: Using IOS to measure lung function can reflect the variation of airway resistance,espicially the small airway resistance and the lung compliance,which is of value for the diagnosis of COPD.