Abstract: According to the conservative subsequences of env gene and long terminal repeat（LTR） of endogenous sheep jaagsiekte retrovirus published in GenBank,env gene and LTR gene of endogenous sheep jaagsiekte retrovirus were amplified by PCR.After purification,the fragment was cloned to pMD18-T vector and sequenced.The sequences were analyzed with MEGA4.1 and DNASTAR software.The results showed that the env gene had complete open reading frame,and it had 99.7% nucleotide acid homology to that of endogenous sheep jaagsiekte retrovirus（AF153615.1） but only 90.6% nucleotide acid homology to that of exogenous sheep jaagsiekte retrovirus（M80216.1）.The deduced amino acid sequence of the endogenous env gene was compared with those included by NCBI using BLAST software.The results showed that it had 100% amino acid homology to that of endogenous sheep jaagsiekte retrovirus（AF153615.1）,and the encoded protein had hydrophilicity.This study provides important reference for studying the regulatory effects of 5′ LTR on endogenous env gene.