Objective：To screen differentially expressed genes between gastric cancer and normal gastric mucosa by bioinformatics analysis；to analyze and predict its value in the development and prognosis of gastric cancer. Methods：RNA-seq data from gastric cancer patients were downloaded from the Cancer Genome Atlas（TCGA） database，and differentially expressed genes were screened using the software R-Studio. The DAVID database was used to perform genetic ontology（GO） enrichment analysis and Kyoto Ency－clopedia of Genes and Genomes（KEGG） pathway analysis for differentially expressed genes. The gene with the most significant differ－ence in expression in the PI3K-Akt signaling pathway was identified for further study：its expression level and clinicopathological were analyzed using UALCAN，the website STRING was used to construct its protein-protein interaction networks，and Kaplan-Meier Plotter was used to analyze its correlation with the prognosis of gastric cancer patients. Results：A total of 5704 differentially expressed genes were obtained，including 1225 up-regulated and 1479 down-regulated protein-coding genes；KEGG pathway analysis identified integrin binding sialoprotein（IBSP） as the key gene. IBSP was highly expressed in gastric cancer tissues（P<0.001），which was signif－icantly associated with the clinicopathological features and poor prognosis in patients with gastric cancer（P<0.05）. Conclusion：As a potential oncogene in gastric cancer，IBSP may regulate the early progress of gastric cancer through PI3K-Akt signaling pathway and lead to poor prognosis of gastric cancer patients，and it is expected to become a new clinical diagnosis and prog－nostic marker for gastric cancer.