Abstract: To construct Mongolia sheep Ghrelin prokaryotic expression vector, and observe its expression in host Escherichia coli strain BL2l(DE3), the cDNA of Ghrelin gene was amplified from abomasum fundic gland mRNA of Mongolia sheep by RTPCR. PCR product was cloned into the T vector pMD19T to construct pMD19TGhrelin for sequencing. Then the cDNA was subcloned into the prokaryotic expressing plasmid vector pET32a(+) and transformed into host Escherichia coli strain BL2l(DE3)for expression. The clone was induced by IPTG and was identified by SDSPAGE and Westernblot. Comparing with the Ghrelin sequence of sheep reported in GenBank, there were two nucleotide differences, but it did not affect the amino acid sequence; the expression product was observed with soluble protein; The result of Westernblot showed that the recombinant protein was recognized by Hisantibody specifically. The nucleotide sequence isolated from the recombinant plasmid pET32aGhrelin was the same as expected; the Ghrelin protein was expressed successfully in Escherichia coli, which provided a basis for further investigation of Ghrelin function.