Abstract: OBJECTIVE To determine the effects of glutamine on the p38 mitogen-activated protein kinases(P38MAPK) activity and IL-17 expression in peripheral blood mononuclear cells(PBMC) of patients with chronic obstructive pulmonary disease(COPD). METHODS Thirty-two patients with acute exacerbation of COPD(AECOPD) were enrolled. After the treatment, all patients’ conditions were controlled in stable COPD(SCOPD). Venous blood of patients was collected in the acute and stable period, and PBMC were extracted immediately. Then divided into glutamine(Gln) group and blank control group. Sixteen healthy people’s PBMC were used as the normal group. The levels of P38MAPK and IL-17gene expression in PBMCs were detected by real-time PCR. RESULTS The levels of P38MAPK and IL-17 gene expression were higher in AECOPD blank control group and SCOPD blank control group than those in the normal group (P<0.01 and P<0.05, respectively). Moreover, there was a significantly increase both P38MAPK and IL-17 gene expression in AECOPD blank control group compared with SCOPD blank control group (P<0.05); The levels of P38MAPKand IL-17 gene expression were higher in AECOPD Gln group than those in the normal group (P<0.05), while there was no significant difference between SCOPD Gln group and the normal group; The levels of P38MAPK and IL-17 gene expression in AECOPD Gln group and SCOPD Gln group were significantly lower than those in blank control group (P<0.01 and P<0.05, respectively). CONCLUSION Gln plays an anti-inflammatory role on COPD patients by inhibiting P38MAPK Cell signaling pathway and reducing the expression of IL-17.