The RNA helicase vasa is a member of the DEAD box protein family that plays an indispensable role in germcell and differentiation of reproductive system. In this study, vasa encoding genes was isolated from gonads of largescale shoveljaw fish (Onychostoma macrolepis) using homologous cloning and the RACE method. The complete cDNA of vasa gene (Gene Bank: HQ412513) contains a 760bp 5' Untranslated Regions (UTR), 1848 bp open reading frame (ORF), encoding 616 amino acids are predicted and 116 bp 3' Untranslated Regions (UTR). A condensed phylogenetic tree was constructed based on the amino acid sequences of the vasa and well-defined vertebrate vasa. The overall topology of the tree showed that the vasa in Onychostoma macrolepis clusters vasa had similarities with vasas of other species. The result enriches our understanding on the high level conservation of the amino acid sequence in the largescale shoveljaw fish. The largescale shoveljaw fish vasa shared 93% sequenced identity with Carassius auratus. The quantitative real-time PCR (qRT-PCR) analysis demonstrated that the vasa encoding gene was detected in intestine, heart, testis, liver, muscle, spleen, brain, cheek, ovary, and mainly detected in testis. During the different concentration of Estradiol, the tesitis vasa mRNA was weakly expressed from the dosage of 8 to 22μg/g body mass (p<;0.05), in the ovary, it was highly expressed at the dosage of 8μg/g body mass (p<;0.05). On the other hand, it was highly expressed in ovary after the muscle injections of Methyltesto sterone, at the dosage of 20μg/g body mass (p<;0.01).