Objective Analyzed the presence of transcription variant of Estrogen receptor of Beagle dogs．Methods According to the reported complete nucleotide sequence of estrogen receptor in NCBI，two pairs of primers were designed and synthesized． The Estrogen receptor cDNA was amplified from the total RNA of the Ovary， uterus，hypothalamus and pituitary of Beagle by reverse transcriptase PCR ( RT-PCR ) ． Then major bands were cloned and sequenced． Results Obtained full-length cDNA sequence of estrogen receptor of Beagle dogs，the major bands were cloned and sequenced ，the results show that the sequence is an Estrogen receptor of Beagle dogs． Conclusion The existence of the transcription variant of Estrogen receptor of Beagle dogs，which was different from ones of Beagle dogs that had been predicted in the online database，It needs further studying．