Abstract: Objective ： The search for differentially expressed genes in gastric cancer and its pre-malignant lesions may help to define molecular alterations in the gastric mucosa tissue that may precede the development of gastric cancer. Methods ： The differentially expressed cDNA bands were isolated and identified by fluorescent differential display (FDD) in 3 gastric cancer, 3 premalignant lesions and 3 normal gastric mucosa tissue and then reamplified by PCR. After being cloned, all cDNA fragments were sequenced. Through BLASTN software, the sequencing results were compared with GenBank database for homology analysis. Northern blot was performed for determining the express of genes. Results ： 2 differentially expressed cDNA fragments were found. One of them was over-expressed in the normal gastric tissue and premalignant lesions and found no homology to known gene sequences in GenBank. A accession number of GenBank was CB833297. One cDNA fragment that was over-ex-pressed in gastric mucosa showed significant homology to known gene sequences (RP11-315A19) in GenBank, but its function is unknown. Conclusion ： The two differentially expressed genes found might be involved in process of the gastric carcinogenesis.