Abstract: Objective：To explore differentially expressed genes and their biological significance in lymph node metastasis of early gastric cancer using RNAseq data from TCGA database. Methods：RNAseq data and clinicopathological data of gastric cancer were downloaded from TCGA database, and early gastric cancer data were screened out and grouped according to the presence or absence of lymph node metastasis. Under R3.5.3 environment, edgeR package was loaded to screen differentially expressed genes of T1N13M0 gastric cancer compared with T1N0M0 gastric cancer. The potential biology function of differentially expressed genes was analyzed by GO function and KEGG pathway enrichment analysis. The correlation between differentially expressed genes and prognosis of gastric cancer was analyzed. Results：A total of 197 significantly upregulated genes and 5 significantly downregulated genes were screened out in early stage gastric cancer with lymph node metastasis. The upregulated differentially expressed genes were significantly enriched in cell proliferationrelated GO functions such as interleukin1, interleukin6, and tumor necrosis factorα (TNFα), and in cancerrelated signaling pathways such as Wnt signaling pathway, NFκB signaling pathway, and gastric cancer signaling pathway. Most of the upregulated and downregulated differentially expressed genes were significantly related to the prognosis of gastric cancer patients. Conclusions：Differentially expressed genes associated with lymph node metastasis in early gastric cancer may affect biological behavior of early gastric cancer through cell proliferationrelated GO functions, Wnt signaling pathway and NFκB signaling pathway, and so on. The levels of most differential expression genes are significantly associated with the prognosis of patients with gastric cancer, and may be used as diagnosis and treatment targets for gastric cancer.