Objective · To investigate the effects of CXCL9 (C-X-C motif chemokine ligand 9) mRNA on the overall survival of ovarian cancer patients, and to explore its relations with immune-related pathways and gene in tumor microenvironment, so as to reveal the significance of CXCL9 in the prognosis of ovarian cancer. Methods · Kaplan-Meier method was used to analyze the relationship between CXCL9 mRNA and the survival of ovarian cancer patients in The Cancer Genome Atlas (TCGA) database. Gene Set Enrichment Analysis (GSEA) was used to assess the biological function of CXCL9 mRNA in ovarian cancer. The correlation of CXCL9 mRNA with cluster of differentiation 8A (CD8A) and immune checkpoint mRNA was analyzed. Results · The high of CXCL9 mRNA was significantly associated with better prognosis in patients with ovarian cancer. GSEA showed that CXCL9 mRNA was enriched in the immune response-related pathway. In addition, Pearson correlation analysis showed that CXCL9 mRNA was positively correlated with the mRNA of CD8A and immune checkpoint. Conclusion · The high of CXCL9 mRNA in ovarian tumor tissue is a good predictor of prognosis, and the mRNA of CXCL9 may be closely related to the recruitment of lymphocytes tumor margin to the tumor microenvironment to exert the function of anti-tumor immune response.