Abstract: Objective:To study the age-related changes of pulmonary function in healthy and chronic obstructive pulmonary diseased aged persons.Methods:The data of five years follow up observation on pulmonary function were collection and analized in 60 cases with senile COPD at remission （mild, moderate and severe COPD, 20 patients in each group） and in 20 cases of healthy aged persons. Results:In all 4 groups the VC, FEV1, FVC and PEF decreased with the increase of age, and their amplitudes of decrement were in the following order: PEF＞FEV₁＞FVC＞VC. The age-dependent declination of these parameters was more marked in patients with COPD than in the health group and more prominaut in severe COPD group than in the mild and moderate COPD groups.Conclusion:The actual values of FEV1, FVC, and PEF, may perfectly reflex the statistical differences among different degrees of COPD. Therefore, the plysician should pay more attention to the early and mild cases with COPD and catch all the possible chances to treat them.