Abstract：Objective：To observe the clinical effect of the therapy of Yiqi Yangyin Decoction combined with western medicine on idiopathic pulmonary fibrosis (IPF) in remission stage. Methods ： A total of 66 patients with IPF in remission stage were divided into the trial group and the control group according to the random number table method， with 33 cases in each group. The control group was given routine western medicine for treatment，and the trial group was treated with Yiqi Yangyin Decoction combined with western medicine. The two groups were treated for two months. The traditional Chinese medicine (TCM) syndrome scores， the semi-quantitative scores of high resolution CT (HRCT)， indexes of lung function， including forced vital capacity (FVC)，forced expiratory volume in one second (FEV1)，peak expiratory flow (PEF) and total lung capacity (TLC)，partial pressure of carbon dioxide (PaCO2) in arterial blood，and partial pressure of oxygen (PaO2) in arterial blood were compared before and after treatment between the two groups； the clinical effects and incidence of adverse reactions in both groups were evaluated. Results： During the trial， 2 cases dropped off in the trial group， and finally 31 cases were included； 3 cases dropped off in the control group， and finally 30 cases were included. After treatment， the total effective rate was 90.32% in the trial group， higher than that of 70.00% in the control group (P＜0.05). After treatment， the TCM scores， HRCT semi-quantitative scores and PaCO2 levels in the two groups were decreased when compared with those before treatment (P＜0.05)，and the PaO2 levels were increased (P＜ 0.05). After treatment，the TCM syndrome score，HRCT semi-quantitative scores and PaCO2 level in the trial group were lower than those in the control group (P＜0.05)，and the PaO2 level was higher than that in the control group (P＜0.05). After treatment， the levels of FVC， FEV1， PEF and TLC in the two groups were higher than those before treatment (P＜0.05)，and the above levels in the trial group were higher than those in the control group (P＜0.05). The incidence of adverse reactions was respectively 9.68% and 13.33% in the trial group and the control group， there being no significance in the difference (P＞0.05). Conclusion：The therapy of Yiqi Yangyin Decoction combined with western medicine has a definite curative effect on IPF in remission stage， which can improve the lung function of patients and mitigate the lung fibrosis with good safety.