〔Abstract〕 Objective To study the clinical effect of carbocisteine in the treatment of patients with acute exacerbation of chronic bronchitis. Methods 56 Fifty-six patients with acute exacerbation of chronic bronchitis diagnosed and treated in the Zhangzhou Guleigang Economic Development Zone First Hospital from January 2022 to December 2022 were selected and treated with carbocisteine oral solution for 7 days. Blood gas analysis indexes, lung function, inflammatory factors and T lymphocytes were detected and compared before and after treatment (7 days after treatment). Results In this study, 56 patients with acute exacerbation of chronic bronchitis were clinically controlled in 36 cases, alleviated in 14 cases, and ineffective in 6 cases. The total effective rate was 89.3 %. After treatment, the hydrogen ion concentration index (pH), arterial partial oxygen pressure (PaO2) and percutaneous arterial oxygen saturation (SpO2) were higher than those before treatment, and the arterial partial carbon dioxide pressure (PaCO2) and bicarbonate radical (HCO3 - ) were lower than those before treatment, the differences were statistically significant (P < 0.05). Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) were all higher after treatment, and the differences were statistically significant (P < 0.05). After treatment, the levels of serum tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), CD3+ , CD4+ and CD8+ cells were lower than those before treatment, and the differences were statistically significant (P < 0.05). Conclusion Carboxymesteine can improve acid-base imbalance, inflammatory response and T-lymphocyte immune status in patients with acute exacerbation of chronic bronchitis, with high curative effect and few adverse reactions.