The full-length cDNA encoding ) using the rapid amplification of cDNA ends technique (RACE). The complete cDNA was 1257 bp long, and contained an open reading frame (ORF) of 1056 bp, a 23-bp 3' untranslated region, and a 178-bp 5' untranslated region. The ORF encoded a polypeptide of 351 amino acids containing a serine/threonine kinase domain and a T-loop. An homology analysis revealed that the Cdk7 of had high identity with those from other species. Quantitative real-time PCR analyses showed that transcripts were present in all of the tissues examined, with the highest transcript levels in the ovary. The high transcript level of in the ovary was consistent with its role in regulating cell division. The mRNA levels in oogonia were higher in the first and the second stages than in the other stages of overy development, indicating that may play an important role in oogonial mitosis. After eyestalk ablation, the transcript levels of significantly increased in the ovary to peak on day 4, and then decreased. Together, these results suggested that Cdk7 may play important roles in ovarian development, especially oogenesis, in . These data provide useful information for further research on the regulation of gonad development in this species and other crustaceans.