Cyclin-dependent kinases (CDKs) are members of the serine/threonine protein kinase family and key regulators of the cell cycle transitions in eucaryon. CDK1, also known as Cdc2 or p34cdc2, is the first documented CDK and is vital for mitosis and meiosis. CDK1 functions as a catalytic subunit by binding with its regulatory subunit cyclin B to form a complex at the transition from G2 to M phase. The gene has been described in several species, but investigations in mollusks are lacking. To study the function of the gene in juveniles of selected (red clams) and natural (yellow clams) populations of gene via rapid amplification of cDNA ends (RACE). The cDNA is 1623 bp long and contains a 353 bp 5' untranslated region (UTR), a 370 bp 3' UTR, and a 900 bp open reading frame (ORF) encoding 299 amino acids. The predicted amino acid sequence of exhibited serval conserved characteristics, including a STKc-CDK1-euk domain, specific sequences of the CDK family DLKPQN and G/V-T/S-X-X-Y/F-X-A-P-E, the cyclin B binding site PSTAIRE, and ATP-coupled-sites GXGXXG and K33. Sequence alignments revealed that kinases from other species. The tissue distribution analyses showed that is expressed in all of the tested tissues. The highest expression was in the gonad, followed by the mantle, suggesting that plays an important role in the cells with active division in the gonad and mantle. In different aquaculture conditions experiments, the red clams grew faster than the yellow clams under high and low light and under high and low algal concentrations. The expression profiles of under different aquaculture conditions were consistent with the growth results that expression level was also higher in the red clams. Therefore, we speculate that is closely related to early juvenile growth and that the light and algal concentrations also play important roles (inappropriate conditions may inhibit juvenile growth). The red clams may possess better growth and development characteristics than the yellow clams. The results of this study contribute to a better understanding of the mechanisms of growth and provide basic information for breeding new varieties of .