The chromosomal fragments of Vibrio Cholerae Classic Biotype and Eltor Biotype were cloned respectively with vector plasmid pUC18 and B.S(M13+). We got recombinants which could express the LPS O-Antigen of Vibrio cholerae, and the expressed O-Antigen expressed had very good specificity and immunogenicity. After analyzing the recombinant plasmids by restriction endonucleases digestion, we found the size of foreign fragments in pMG-301 and pMG-302 were 8.4 kb and 7.6 kb, which were much smaller than 16 kb fragment reported by documents and great difference existed between the gene's structure.