Abstract: OBJECTIVE To observe the effects of tonifying Qi, promoting blood flow and dredging collaterals treatment on IL-6/JAK/STAT signaling pathway of pulmonary vascular remodeling of COPD rats. METHODS Fifty SD rats were randomly divided into normal control group, model group, Chinese medicine group, western medicine group, and integrated Chinese and western medicine group. The rat model of COPD was established by intratracheal instillation of LPS and daily exposure to cigarette-smoking. The pathological features of pulmonary arteries were observed by microscope after intervention of drugs. The serum contents of IL-6 was detected by ELISA. The expressions of p-JAK2 and p-STAT3 were detected by Western blot. The content of the protein expression levels of PCNA in pulmonary artery were detected by immunohistochemistry. RESULTS The serum content of IL-6 and protein expression levels of PCNA in each drug group was significantly lower than in model group (P<0.05 or <0.01). P-JAK2 and p-STAT3 expression level in each drug group was significantly lower than in model group (P<0.01). P-JAK2 expression level in integrated Chinese and western medicine group was lower than in Chinese medicine group and western medicine group significantly (P<0.01). CONCLUSION Tonifying Qi, promoting blood flow and dredging collaterals treatment may reduce the remodeling of pulmonary vascular by the way of inhibiting the activation of IL-6/JAK/STAT signal pathway, which can lead to regulate the protein expression levels of PCNA.