Abstract:To construct expressing vector carrying esat6 gene and express this protein in Streptococcus gordonii GP251. esat6 gene was amplified by PCR with specific primer from genome of Mycobacterium tuberculosis (MTB)H37Rv. Inserted esat6 into the pMD18-T vector by T/A clone to get recombinant vector pMD18-esat6. Then digested pMD18-esat6 with restriction enzyme, esat6 was cloned to vector PSMB104 and expressed in Streptococcus gordonii GP251. The expression of esat6 protein was detected by Tricine-SDS-PAGE and Western-blot, ELISA technique was also used to detect its secretory volume. Restriction endonuclease, PCR, Tric ine-SDS-PAGE and Western-blot confirmed that esat6 gene was cloned into expressing vector successfully, and a 10 kD protein secreted in Streptococcus gordonii GP251, this protein has a good immunogenicity. The expression vector of esat6 gene was constructed, and esat6 protein expressed in Streptococcus gordonii1 successfully, it will be benefit for future study.