Transforming growth factor-beta1 (TGF-beta1) is a multifunctional cytokine that is produced in the platelet, bone, placenta, and other tissues. It acts as a growth inhibitor in many types of cells, and also mediates extracellular matrix production and immunosuppression. Mutations in the specific domain of its gene ( TGFB1) cause Camurati-Engelmann disease, a bone-sclerosing disorder, and those in other domains may be associated with osteoporosis. We identified 106 single-nucleotide polymorphisms and 11 other types of variations in TGFB1and six other genes. These genes were TGF-beta type I receptor gene (TGFBR1), TGF-beta type II receptor gene (TGFBR2), SMAD2 gene (SMAD2), SMAD3 gene (SMAD3), SMAD4 gene (SMAD4), and SMAD7 gene (SMAD7), all of which compose the TGF-beta1 signaling pathway. We also estimated allele frequencies of these DNA polymorphisms among 48 Japanese individuals. Our data will provide a useful resource for the study of disease susceptibility.