A strain screened from the waste water of an oilfield can produce insoluble extracellular polysaccharide used in selective plugging which is instrumental in microbially enhanced oil recovery. However this strain is sensitive to high temperature and produces little extracellular polyssacharides above 40 ℃. Therefore pET-ecoRRF, pET-tteRRF and corresponding control plasmids were transformed into the strain. The new strain can grow in 45 ℃, and western-blot indicates that the RRF genes have been expressed noticeably in the transgene strains. It has been showed that the transgene strains are able to bear higher temperature, and the sustainable temperature is higher five to eight degrees than the original strain. Because Enterobacter sp. is related to Escherichia coli, the expression of RRF is better than the gene of Thermus thermophilus in the strain of JD. At last it is successful to get a genetic engineering microbe which can endure the temperature as high as 45 ℃ and produce extracellular polysaccharides.