Abstract： Objective： To observe the clinical effect of Xingsu pectoral syrup combined with theophylline sustainedrelease tablets for chronic bronchitis. Methods：A total of 150 cases of patients with chronic bronchitis were divided into the control group and the study group according to the random number table method，75 cases in each group. The control group was treated with theophylline sustained- release tablets， and the study group was treated with Xingsu pectoral syrup combined with theophylline sustained- release tablets. Both groups were treated for four weeks. Before and after treatment，the levels of inflammatory factors，vasoconstriction and blood oxygen concentration in the two groups were compared. After treatment，the disappearance time of clinical symptoms and the lengths of hospital stay in the two groups were compared. Results：Before treatment，there was no significant difference being found in the comparison of the levels of interleukin-2(IL-2)，interleukin-6(IL-6) and hypersensitive C-reactive protein(hs-CPR) between the two groups(P＞0.05). After treatment，the levels of IL-2 in the two groups were increased when compared with those before treatment(P＞0.05)， and the levels of IL-6 and hs-CPR were decreased(P＞0.05)；the improvement of each index in the study group was more significant than that in the control group(P＜0.05). Before treatment，there was no significant difference being found in the comparison of plasma endothelin-1(ET-1) levels between the two groups(P＞0.05). After treatment，ET-1 levels in the two groups were decreased when compared with those before treatment(P＜0.05)，and the level in the study group was lower than that in the control group(P＜0.05). Before treatment，there were no significant difference being found in the comparison of the levels of blood oxygen saturation(SaO2)，partial pressure of blood oxygen(PaO2) and partial pressure of carbon dioxide (PaCO2) between the two groups(P＞0.05). After treatment， there was no significant difference being found in the comparison of SaO2 levels between the two groups(P＞0.05)；PaO2 levels in the two groups were increased when compared with those before treatment(P＜0.05)， and PaCO2 levels were decreased(P＜0.05)； the improvement of the above two indexes in the study group were more significant than that in the control group(P＜0.05). After treatment，the relief time of coughing，expectoration and wheezing as well as the lengths of hospital stay in the two groups were shorter than those in the control group， the difference being significant(P＜0.05). Conclusion： The therapy of Xingsu pectoral syrup combined with theophylline sustained- release tablets has an ideal effect in treating chronic bronchitis， which can quickly relieve clinical symptoms，improve the blood oxygen concentration and vasoconstriction in patients，reduce inflammatory responses，thus shortening the length of hospital stay.