Abstract: Cyclin T is a critical factor that stimulates the process of transcription elongation. We obtained the full-length cDNA sequence of cyclin T from black tiger shrimps (Penaeus monodon)(denoted as Pmcyclin T) by RACE PCR. The cDNA of Pmcyclin T was 3 421 bp, encoding a polypeptide of 1 044 amino acids. Bioinformatics analysis shows that the amino acid sequence contained a CYCLIN conserved region of a periodic protein family as well as N-glycosylation sites and phosphorylation sites. The results of Blast and phylogenetic analyses suggest that Pmcyclin T shared very high homology with other kinds of arthropod such as Diaphorina citri, Acromyrmex echinatior and so on. Besides, we measured the mRNA expression of Pmcyclin T in seven tissues by real-time PCR. Expression was highest in the ovary and moderate in the intestine, brain and so on. While at different stages of ovary, Pmcyclin T was highest expressed at Stage Ⅲ, suggesting that Pmcyclin T might play an important role in ovary development of black tiger shrimp.