Background: Idiopathic pulmonary fibrosis (IPF) has a poor prognosis and is often a kind of heavy financial burden to patients.Currently,few treatments are available for IPF.Clinical practice of traditional Chinese medicine (TCM),using a syndrome differentiation approach,offers some treatment success in IPF.However,there is no sufficient evidence-based study of the role of TCM in IPF management to make strong conclusions.This study evaluates the efficacy and safety of TCM in the treatment of IPF.Methods and design: A multicenter,exploratory,randomized,double-blind and placebo-controlled trial is planned.A total of 80 patients will be enrolled in the study,which will include 26 weeks of treatment.Participants will be randomly assigned into TCM group or control group in a 1:1 ratio.The TCM group will be given TCM granules based on syndrome differentiation.Formulae include Bao-fei Hua-xian granule for lung qi deficiency,Jin-shui Huan-xian granule for lung-kidney qi deficiency and Yang-qing Kang-xian granule for yin deficiency and inner heat.The control group will be given a corresponding TCM granule placebo.The efficacy and safety of interventions will be evaluated by the outcome variables,including frequencies of acute exacerbations,pulmonary function,clinical symptoms,dyspnea,healthrelated quality of life (HRQoL).6-minute walk distance and safety indicators.Discussion: It is hypothesized that TCM will decrease the frequency of adverse events,improve pulmonary function and HRQoL,based on our clinical experience.This trial is the first study of TCM treatment in IPF that is based on syndrome differentiation and will evaluate the efficacy and safety of TCM in IPF.Trial registration: This study was registered on www.Chictr.org.cn: ChiCTR-IIR-17013532.Register date: November 24,2017.