Introduction: AG NPP709 (SynaturaⓇ) was already proved to be superior in suppressing cough and sputum in patients with upper respiratory infection in previous phase III study. Thus, it can be assumed that AG NPP709 is effective in COPD patients with chronic bronchitis type. Methods: Chronic bronchitis type COPD patients 1) over the age of 40 years with smoking history more than 10 pack years, and 2) with symptoms of chronic bronchitis including cough and sputum for more than 3 months were enrolled. This prospective open-label single-arm clinical trial examined clinical efficacy through pulmonary function test (PFT), COPD assessment test (CAT) scores and systemic inflammation state assessed by CRP, fibrinogen, IL-6, TNF-α and IL-33. A total of 30 patients enrolled and received a follow-up test after taking AG NPP709 for 3 months. Results: All patients were male, mean age was 71.93±7.93. 100% were ever smokers and mean smoking history was 46.86±24.96 pack-years. The mean post-BDR FEV1/FVC was 58.63±11.4, FEV1 (%) was 75.93±20.07. The mean total CAT score was 14.76±7.14. Of this patients, 26 were followed up after 3 months. In paired t test, significant improvement (p＜0.05) was observed in total CAT score (p=0.005), fibrinogen (p=0.013). 3 patients experienced mild gastrointestinal side effects such as nausea. Conclusion: AG NPP709 improved the symptoms and improved systemic inflammation by significantly reducing fibrinogen levels. This study suggests that AG NPP709 can be used with efficacy and safety in chronic bronchitis type COPD patients.