Abstract: Thioredoxin proteins maintain the stability of the redox state and are involved in essential antioxidation and oxidation reduction process regulation in insects. In order to reveal the functions of the thioredoxin proteins gene and its transcription regulated by Scleroderma guani parasitization, this study cloned the fulllength cDNA sequence of thioredoxin gene from Tenebrio molitor by rapid amplification of cDNA ends strategy. The fulllength cDNA sequence of thioredoxin gene was 531bp, and contained a 318bp open reading frame encoding 106 amino acid residues, with 3′ and 5′ untranslated regions of 95bp and 119bp,respectively.Its predicted molecular weight and isoelectric point were 1197kDa and 422, respectively. Its deduced amino acid sequence contained a highly conserved CGPC active site at the Nterminus. Multiple sequence alignment analysis showed that thioredoxin of Tmolitor shared over 60% amino acid identities with those of other insects. qPCR analysis showed that thioredoxin gene was expressed at different developmental stages of Tmolitor with the highest expression in the pupa and the lowest in the adult. This gene highly expressed in fat body of pupae. After 6h parasitization by Sguani, the relative expression of thioredoxin gene was obviously upregulated.