Idiopathic inflammatory myopathies (IIMs) are autoimmune diseases influenced by genetic background and environmental factors. Recently, FAM167A-BLK gene has been identified as a potential genetic susceptibility locus for dermatomyositis (DM) in patients of European and Japanese populations. Our aim here was to investigate the association between FAM167A-BLK polymorphisms and IIMs risk in Chinese Han. The FAM167A-BLK single nucleotide polymorphisms (SNPs) rs2736340, rs7812879, rs13277113, rs2618479, rs2254546 and rs2248932 were analyzed in polymyositis (PM) patients (n = 310), DM patients (n = 535) and 968 ethnically matched healthy controls, with the Sequenom MassArray system. Our present study demonstrated that strong allele association was observed in overall PM/DM and PM patients for rs2736340 (P c = 6.48 × 10(-3); P c = 0.013, respectively), rs7812879 (P c = 0.017; P c = 0.034, respectively) and rs13277113 (P c = 0.011; P c = 0.047, respectively). These three SNPs were significantly associated with interstitial lung disease (ILD) in overall PM/DM patients (all, P c < 0.05). The frequency of the five haplotypes of the five SNPs (rs2736340, rs7812879, rs13277113, rs2618479 and rs2254546) was also significantly different between overall PM/DM, PM or DM patients and healthy controls. This was the first study to demonstrate that the FAM167A-BLK polymorphisms were associated with Chinese PM/DM patients or these patients with ILD, indicating that PM/DM might share common gene with other autoimmune diseases.