Objective: To investigate the value of monitoring the pulse oxygen saturation(SpO2) during walking in the stable chronic obstructive pulmonary disease(COPD) patients. Methods: Twenty-three patients with stable COPD were selected, 20 healthy adults without previous respiratory disease were selected as the control group. SpO2 were monitored during treadmill exercise. The differences between the two groups were compared. The correlation between SpO2 and pulmonary function, COPD assessment test (CAT) score, modified medical research council dyspnea scores(mMRC) and the number of acute execration in the past year were analyzed. Results: ①The nadir SpO2 of the COPD group during the exercise(SpO2ML) was lower than the control group during the exercise with highly significant differences (P<0.05). ② SpO2ML was associated with forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1%pred and was no significant correlation between FEV1/FVC, maximum ventilatory volume per minute(MVV) and diffusion capacity for carbon monoxide per liter of alveolar volume (DLCO/VA). The acute execration during the past 1 year was not associated with SpO2ML. ③ The CAT score had no significant correlation between the rest SpO2, SpO2ML and ΔSpO2. The mMRC score was associated with SpO2ML, ΔSpO2 and had no significant correlation with the rest SpO2. Conclusion: ①COPD patients are more likely to be exercise-induced hypoxemia. The worse the lung function, the more significant decline in SpO2. ②SpO2ML could be a predictive indicator of the COPD management when the cardiovascular disease was ruled out, and will be a clinical indicator for COPD screening.