Objective To observe the genotype distribution of Haemophilus parainfluenzae from patients with acute exacerbations of chronic obstructive pulmonary disease ( AECOPD) and their effects on A549 cells. Methods 80 hospitalized patients with AECOPD in our hospital were enrolled. Haemophilus parainfluezae were collected by sputum culture and genotyped, then inoculated with cell line A549. IL-6 and IL-8 concentrations in the supernatant were detected and cell morphology was observed at different time points. Results The patients were divided into three groups according to their symptoms. 15 Haemophilus parainfuenzae strains were collected and the positive culture rate between type 1 and type 3 COPD patients were statistically different. The concentrations of IL-6 and IL-8 were both significantly higher than control and increased as time passed. 4 genotypes were got by random amplification of polymorphic DNA ( RAPD) . In RAPD Ⅲ group, the IL-8 concentration was higher at 12h and 24h than others. No morphologic change was found in the cells inoculated with Haemophilus parainfuenzae by microscope after fixing. Conclusions Positive culture rate of Haemophilus parainfuenzae was different in different COPD groups according to symptoms. Haemophilus parainfuenzae can stimulate a cytokine response in A549 cells, maybe one of the pathogens of AECOPD, especially the RAPDⅢ type. Haemophilus parainfuenzae is not an intracellular bacteria.