Some proteins or enzymes play physiologic roles depending on its biotinylation via catalyzation of holocarboxylase synthetase (HCS), such as histones and carboxylases. So far, our understanding of HCS function is mainly from the researches on human cell lines. In order to understand the role of protein biotinylation in fish development, we cloned full length HCScDNA sequence with 2 942 bp. Intergrity open reading frame encodes 829 amino acids, containing conserved BirA ligase domain close to C termino. Further investigation using whole mount RNA in situ hybridization shows that HCSgene is expressed in wide tissues such as brain, spine cord, gill, heart, intestine and sarcomere, indicating that it might play universal roles during organs development. It is interesting that HCS gene is expressed in whole sarcomere at new hatching larvae, whereas at 6 DAH (day after hatching) larvae, expression signal of HCSgene concentrated on the middle of each sarcomere. Above results may be helpful for future studies on HCS function during fish development.