AIM:To screen the gene expression profiles of normal gastric mucosa,primary gastric cancer and metastatic lymph nodes by gene expression microarray and the associated genes with lymph node metastasis by bioinformatics. METHODS:The differentially expressed genes of nontumorous gastric mucosa (group A),primary gastric cancer (group B) and metastatic lymph nodes (group C) were screened by gene expression microarray obtained from Affymetrix company. The results were further analyzed by bioinformatic software including Gene Expression Profiles Analysis of Cohort Experiment,Gene Ontology Enrichment Analysis and Pathway Significant Analysis. The expression of TLN1 in group A,B and C were confirmed by real-time reverse transcription PCR. RESULTS:278 genes were persistent up-regulated in group A,B,C,which participated mainly in immunologic responses,cell adhesion,phosphate transport,inorganic anion transport,cell chemotaxis,cell motility and signal transduction. While 387 genes were persistent down-regulated in group A,B,C,which were concerned with digestion,glucide metabolism,lipid metabolism,protein metabolism,one-carbon compound metabolism,nitrogen compound catabolism and cell adhesion. The pathway analysis suggested that integrin-mediated cell adhesion pathway were abnormally regulated. These genes including THBS1,TLN,CAPN3,ITGAX,SORBS1,CAPN6,CAPN9 were continuous up-regulated or down-regulated in integrin-mediated cell adhesion pathway. The expressions of TLN1 in group A,B,C were 0.0000342?0.0000711,0.1064?0.1251 and 0.2886?0.3529,respectively. The expression of TLN1 in metastatic lymph nodes was significantly higher than that in nontumorous gastric mucosa and primary gastric cancer (P