Abstract: Objective To explore the changes of cellular immune function in chronic obstructive pulmonary disease patients with infection, and to provide a theoretical basis for COPD patients. Methods Totally 80 patients with COPD complicating infection treated in our hospital from January 2016 to April 2017 were selected as the observation group, contemporaneous 64 patients with simple COPD were selected as the COPD group and 60 healthy people as the control group. The indexes of cellular immunity functions were analyzed in 3 groups. Results (1) In COPD infection group, the average percentage of peripheral blood NK was 19.86 + 10.67, and lower than the COPD group (26.47±10.05) , the difference was statistically significant (P < 0.01) , higher than that of the control group (16.89±5.07) , but the difference was not statistically significant (P > 0.05) . (2) CD3+ cells in peripheral blood of COPD patients with bacterial infection group, COPD group and healthy control group (total T lymphocyte percentage) were (66.64±11.03) , (64.6±11.45) and (67.06±5.55) , there was no significant difference between the three groups (P > 0.05) . (3) In COPD infection group, the peripheral blood CD4 cells and CD4/CD8 ratio were (40.47±10.44) and 1.82 (1.78, 2.57) , higher than the healthy control group[35.01 +7.16 and 1.19 (0.96, 1.66) ], the level of CD8 cells was (23.6±9.82) , lower than the healthy control group (27.50±5.85) , the differences were statistically significant (P < 0.01) ;and COPD group level[ (39.89±9.92) , 2.02 (1.44, 2.83) ] and (21.12±7.64) , there were no statistically significant difference. Conclusions In patients with COPD, the adjuvant immune cell levels are increased but the specific killing immune cells are decreased, on this basis, increased levels of nonspecific killing immune cells help fight infection, immune regulation therapy for COPD patients should focus on improving the level of destruction of immune cells.