Full length cDNA of silver carp transferrin,Hypophthalmichthys molitrix,was first cloned using reverse transcription polymerase chain reaction (RT-PCR) and SMART RACE methods.The entire transferrin cDNA sequence is 2 365 bp long and the open reading frame is 2 025 bp and encodes a protein with 674 amino acids.Molecular characteristics of the gene were forecasted by online molecular softwares.The results showed that it is composed of two domains,with a signal peptide of 15 amino acids which located at the 21st amino acid of N-terminal.Silver carp transferrin gene has high homology with the other species,sharing the highest identity of 74% with grass carp Ctenopharyngodon idella. Phylogenetic tree analysis revealed that transferrin of five Cyprinid fish,Danio rerio,Carassius auratus,Cyprinus carpio,Ctenopharyngodon idella and Hypophthalmichthys molitrix were classified together.Siler carp transferrin mRNA only expressed in liver and spleen (a higher expression level in liver).During embryogenesis,the expression of transferring mRNAs was first detected at the gastrula stage and the expression level increased steadily until the tail bud embryo.Transferrin mRNA showed marked reduction after the stage of tail bud embryo until larvae.Results from the present study indicated that transferrin played an important role in organogenesis during embryogenesis.