Idiopathic pulmonary fibrosis (IPF) is a progressive and often fatal form of interstitial lung disease.Despite extensive efforts in research during recent years,the mechanisms of the disease remain poorly understood.Evidence of an inflammatory mechanism,both supportive and contrary,is briefly reviewed in this paper.However,growing evidence has indicated that the apoptosis of alveolar epithelial cells (AECs) may be the early driving force of progression,with subsequent disrupted integrity of the alveolar-capillary basement membrane leading to an abnormal wound healing pathway.Thus,this paper will focus on outlining a process of pathogenesis of IPF from initial apoptosis of AECs to end lung remodeling.