Abstract: In order to analyze the function of a differential expression cDNA fragment of gonads of domesticated broodstock black tiger shrimp (Penaeus monodon), the black tiger shrimp eukaryotic translation initiation factor 3 subunit G (btseIF3g) had been found by spliced with the EST, after screening in the P.monodon mix cDNA library. The full length cDNA of btseIF3g (GenBank accession no. FJ829364) contained a 5′ untranslated region (UTR) of 72 bp, a 3′UTR of 90 bp and an ORF of 879 bp encoding a polypeptide of 292 amino acids with an estimated molecular mass of 32.97 kDa. RNA recognition motif (RRM) was found in the btseIF3g deduced amino acid sequence. Phylogenetic analysis of the eIF3 gene family indicated that the btseIF3g was homologous to the eIF3g. mRNA expression of btseIF3g could be detected in 250-day-old P.monodon′s eyestalk, brain, hepatopancreas, gonad and muscle by fluorescent quantitative real-time PCR analysis. The highest expression level of btseIF3g in the ovary indicated that btseIF3g played an important role in oogenesis.