Idiopathic pulmonary fibrosis (IPF) is a progressive diffuse interstitial lung disease with poor prognosis of unknown etiology that leading ultimately to death. Predisposing factors are thought to have environmental and genetic inputs.We investigated the relationship between HLA-A, B gene polymorphism and idiopathic pulmonary fibrosis (IPF) in a Han Chinese population.The gene frequency of 36 patients with IPF was detected using a PCR-SSP grouping method. These values were compared with those a Bone Marrow Bank (Shanghai, China) of healthy subjects of identical racial origin as the patient group.The gene frequency of HLA-A*3 (3.5%), HLA-B*14 (1.4%), -B*15 (10.2%), and -B*40 (5.0%)of the IPF group increased significantly (Pc < 0.05) compared with that in the control group HLA-A*3 (1.0%), HLA-B*14 (0.1%) and -B*15 (1.1%) and -B*40 (0.8%). Investigation of the link between the HLA-A and -B gene showed the gene frequency of HLA-A2B15 to be 5.0% as well as -A2B40 (4.3%), -A11B15 (5.0%), -A24B48 (2.8%) and -A30B40 (2.8%), which were significantly higher than those of the control group (Pc < 0.05).These data suggest that the gene frequency of HLA-A*3, HLA-B*14, -B*15, -B*40, and the linked gene frequency of HLA-A2B15, -A2B40, -A11B15, -A24B58, -A30B40 is associated with IPF pathogenesis.