To explore the application of impulse oscillometry (IOS) in the estimation of airway obstruction and to evaluate the correlation between spirometry indices and IOS parameters.From Nov.2007 to May 2008, spirometry and IOS measurements were performed in 100 participants (male 72, female 28). FEV(1), FVC, FEV(1)/FVC, airway resistance at 5 Hz (R(5)), airway resistance at 20 Hz (R(20)), central resistance (Rc) and peripheral resistance (Rp) of structural parameters interpretation graph, FEV(1)% pred, R(5)% pred, R(20)% pred, and FEV(1)/FVC were analyzed. Correlations between spirometry and IOS parameters were studied.All participants had satisfactory impulse oscillometry results. R(5) and Rp were significantly increased in FEV(1)/FVC < 70% group [(5.3 +/- 2.1) and (6.2 +/- 2.9) cm H(2)OxL(-1)xs(-1) (1 cm H2O = 0.098 kPa)], respectively. There was significant negative correlation between FEV(1) and R(5) and Rp (correlation coefficient was -0.38 and -0.47 respectively, all P < 0.01). There was also negative correlation between FVC and R(5) and Rp (correlation coefficient was -0.28 and -0.37, respectively, all P < 0.01). A significant negative correlation between FEV(1)% pred, FVC% pred, FEV(1)/FVC% pred and R(5)% pred was also observed (correlation coefficient -0.49, -0.39 and -0.43, respectively).IOS parameters can be used to evaluate airway obstruction. Among IOS parameters, R(5) was the most sensitive, which was also significantly correlated with spirometric parameters.