OBJECTIVE: To evaluate the effects of Qizhukangxian granules(QG) on idiopathic pulmonary fibrosis(IPF).METHODS: This is a randomized, double blind,placebo-controlled and multicenter clinical pilot trial. Six medical centers in Tianjin, China, participated in the study. A total of 120 IPF patients were enrolled and randomized into two groups,with 60 patients in each group. The treatment group was treated with QG, while the control group received a Qizhukangxian placebo. The pharmacological treatment lasted for 48 weeks from the enrollment date. The indexes of patients were recorded on the admission day and at the end of the 24 th and 48 th weeks. Data were analyzed to study the effects of QG; forced vital capacity, change in forced vital capacity and maximal 6-min walk test(6 MWT) distance were the primary endpoints. Secondary endpoints were percentage of patients with episodes of acute exacerbation of IPF, pulmonary function, changes in pulse oxygen saturation during the 6 MWT, dyspnea score, St. George's respiratory questionnaire score, arterial blood gas analyses and the total Traditional Chinese Medicine symptom pattern score.RESULTS: After 24 weeks of treatment, QG showed greater efficacy than the placebo in certain parameters, including the dyspnea score, Traditional Chinese Medicine symptom pattern score and some indicators in the St. George's respiratory questionnaire score. Analysis of the indexes obtained from all patients at the end of the 48 th week showed that the therapeutic effects in the treatment group were significantly better than those in the control group because remarkable differences were observed in most of the primary and secondary endpoints between the two groups, except for the maximal distance of the 6 MWT and arterial blood gas analyses. No adverse reaction was observed in either group during the 48-week trial treatment period.CONCLUSION: QG could effectively treat IPF patients by ameliorating pulmonary function, improving the quality of life and lowering the percentage of acute exacerbations.