The full length cDNA of ?1,3 galactosyltransferase gene was amplified by RT PCR from the peritoneal macrophages of BALB/c mice, which was subcloned into an eukaryotic expression vector pCDNA3 1/V5 HisA, and it was confirmed by DNA sequencing. The gastric cancer cell GC9811 was transfected with pCDNA3 1/V5 HisA?1,3GT by Lipofectamine TM 2000. The positive clone was screened by G418 for two months and confirmed by RT PCR. The gastric cells expressing Gal?(1,3)Gal epitope were detected by immuohistochemisty, and they were killed by naive antidoby specific to Gal?(1,3)Gal epitope. The results showed that the pCDNA3.1/V5 HisA?1,3GT was successfully constructed, and the transfected gastric cancer cells could highly express Gal?(1,3)Gal, which promoted lysis of the cancer cells by normal human serum.