Thioredoxin interacting protein (TXNIP), which plays a regulatory role in lipid metabolism and immune regulation, is down-regulated expressed in F(1) hybrids Landrace × Yorkshire skeletal muscle. Here we described the molecular characterization of porcine TXNIP gene. The full-length cDNA contains a coding sequence of 1,176 bp nucleotides with untranslated regions of 263 bp at 5'-end and 441 bp at 3'-end, respectively. The predicted molecular mass and isoelectric point of porcine TXNIP is 43.81 kDa and 7.385, respectively. The deduced 391 amino acids exhibit high identity with other mammalian TXNIP. The TXNIP gene contains eight coding exons and seven non coding introns, spans approximately 3,348 bp. The expression of porcine TXNIP mRNA is almost absent in Landrace × Yorkshire and lower level in 6-month-old pigs during skeletal muscle development. Other stages and breeds were high level expressed. Statistical analysis showed the TXNIP gene polymorphism (c.575-4T>C) was different between F(1) hybrids and their parents, was highly associated with dressing percentage (DP) and thorax-waist fat thickness (TFT) in the Yorkshire × Meishan F(2) population. The possible role of TXNIP was discussed.