Result: Parameters of pulmonary function tests had been decreased: FVC: 2.81 ± 0.52L, FEV1: 1.85 ± 0.34L, FEV1%: 53.10 ± 22.90%, Respiratory resistance Rrs5 and Rrs20 were higher and reactance Xrs more negative in exacerbations COPD patients than in stable COPD patients.