Abstract: Objective To observe the effect of Jieqin Decoction on serum proinflammatory factors, oxygen free radical and pulmonary function in patients with stable stage bronchiectasis differentiated as phlegm-heat obstructing lung. Methods A total of 70 patients with stable stage bronchiectasis differentiated as type of phlegm-heat obstructing lungs were randomly divided into experimental group and control group, with 35 cases in each group. Both groups were treated with conventional western medication, while Jieqin Decoction was added in the experimental group. The treatment course lasted for 30 days. Comparison of proinflammatory factors, oxygen free radical and pulmonary function before and after treatment in both groups were performed. Results After treatment, serum interleukin-8(IL-8), tumor necrosis factor-α(TNF-α)and malondialdehyde(MDA)levels were significantly decreased in the two groups(P<0.01), and the experimental group was significantly lower than the control group(P<0.05). Superoxide dismutase(SOD)level increased significantly only in the experimental group(P<0.05). After treatment, the pulmonary ventilation function indicators ［percentage of forced vital capacity to the predicted normal value(FVC%pred), percentage of forced expiratory volume in the first second to the predicted normal value(FEV_l%pred), percentage of forced - expiratory volume in the first second to forced vital capacity(FEV_l/FVC)］of the two groups were significantly improved compared with the treatment before(P<0.01), and the improvement of the experimental group was more significant than that of the control group(P<0.05). The improvement of pulmonary ventilation function［percentage of carbon monoxide dispersion to predicted value(DLCO%pred), and percentage of carbon monoxide dispersion per alveolar volume to expected value(DLCO/VA%pred)was more obvious in the experimental group after treatment compared with treatment before(P<0.05), but there was no significant difference between the two groups(P>0.05). Conclusion Combining conventional western medicine and Jieqin Decoction can not only relieve inflammation and peroxidation in patients with bronchiectasis, but also partially prevent or slow down the decline of pulmonary function.