Objective　To study the immune change at low atmospheric temperature in patients with chronic obstructive pulmonary disease (COPD) and the effect of immunopotentiators given before the temperature is decreased on the immune of COPD patients.　Methods　One hundred COPD

patients recruited in this study were randomly divided into baseline group (n=70) and immunopotentiator-treatment group (n=30). IgG

IgA

IgM in blood and CD3

+

CD4

+

CD8

+

CD4

+

/D8

+

in sputum from the two groups were detected respectively at baseline and low temperature. Respiratory infection was recorded during follow-up. Results　The level of IgG and IgA was decreased

the number of CD3

+

and CD8

+

was increased while the number of CD4

+

and CD4

+

/CD8

+

was decreased in baseline group at low temperature. (P0.05). The number of CD4

+

/CD8

+

in sputum was negatively related with respiratory infection at normal temperature

but better related with respiratory infection at low temperature

(－0.661 and －0.612 in baseline group

and －0.901 and －0.936 in immunopotentiator-treatment group).　No difference was found in immune between baseline group and immunopotentiator-treatment group before and after the atmospheric temperature was changed. However

the respiratory infection rate was significantly lower in immunopotentiator-treatment group than in baseline group（P0.05）.　Conclusion　The immunity of COPD patients decreases with the decreasing atmospheric temperature. Local immune of the airway should be assessed by inducing CD3

+

CD4

+

CD8

+

CD4

+

/D8

+

in sputum. Immunopotentiators can increase the body’s immunity but have little effect on local immune of airway.