Abstract: We cloned the complete cDNA sequence of Ubiquitin-conjugating enzyme gene from black tiger shrimps (Penaeus monodon) (PmUbc) by rapid amplification of cDNA ends (RACE) methods based on the partial sequence of PmUbc obtained from the hepatopancreas transcriptome database. The cDNA of PmUbc was 598 bp, including 154 amino acids with an open reading frame (ORF) of 465 bp, 17 bp of 5 'untranslation region (UTR) and 116 bp of 3UTR. Blast analysis shows that PmUbc shared high identity with Ubiquitin-conjugating enzyme of Litopenaeus vannamei. Real time quantitative PCR analysis reveals that PmUbc was constitutively expressed in seven selected tissues (brain, thoracic nerve, heart, hepatopancreas, ovary, muscle, hemolymph). The PmUbc mRNA expression reached the maximum at Stage Ⅲ of ovarian development, followed by StageⅠand Ⅳ. It is concluded that PmUbc might play an important role in ovarian development of P.monodon.