Endocrine disruption seems to be related to high vitellogenin(Vg)levels in male fish and has emerged as a useful biomarker of exposure to estrogenic substances.In this study,we show full-length cDNA sequence of swordtail fish vitellogenin C(Vg C)to provide a basis for assessing estrogenic effects of endocrine disrupting compounds in aquatic environment.Full-length Vg C gene cDNA of swordtail fish were obtained using reverse transcription polymerase chain reaction(RT-PCR)and rapid amplification of cDNA ends(RACE)techniques with total RNA extracted from liver of a swordtail fish after treatment with 17β-estradiol(E2).The result of sequence analysis indicated that the full-length of swordtail fish’s Vg C cDNA is 4 011 bp,containing an open reading frame(ORF)of 3 753 bp which encodes a 1 250 amino acids protein with deduced protein molecular weight of 141.7 ku.The comparation results showed that the nucleotide homology of Vg C was 57%-92% and amino acid homology of Vg C was 44%-85% between swordtail fish and other ten teleosts.Furthermore,expression profile of Vg C mRNA in different tissues and time intervals of swordtail fish was determined by realtime fluorescent quantitative PCR.The result showed the swordtail fish’s Vg C mRNA was mainly detected in liver and weakly in spleen,kidney,ovary.After exposure to E₂,Vg C mRNA expression quantified in liver of swordtail fish had reached a peak on the fifth day,and then the expression level declined gradually.The data obtained from present study provided valuable information for research on reproduction and physiology and application of environmental pollution monitoring of swordtail fish.