Abstract: Objective To evaluate the sensitivity and specificity of CD8+CD28+/CD8+CD28- T lymphocyte balance in predicting the gastrointestinal hemorrhage (GH) in patients with inflammatory bowel disease (IBD). Methods Forty-nine IBD patients, including 30 with ulcerous colitis (UC) and 19 with Crohn’s disease (CD), were enrolled to test peripheral blood CD8+CD28+ and CD8 + CD28- T cells using flow cytometry. All the patients were followed up for one year. The receiver-operating characteristic (ROC) curves were used to test the efficiency of CD8+CD28+/CD8+CD28-T lymphocyte balance to predict GH. The differences in lasting time of remission (LTR) under different factors were compared using Kaplan-Meier survival analysis, and the correlation between CD8 + T lymphocytes and the factors were analyzed. Results The utilization rates of immunosuppressant, steroids, and biological agent (BA) were significantly higher in CD patients than in UC patients (P=0.003, 0.043 and 0.002, respectively). The frequencies of CD8+CD28+T cells were obviously higher in UC patients than those in CD patients (t=3.022, P=0.004). CD8+CD28+T cells, CD8+CD28- T cells, and especially CD8+CD28+/CD8+CD28- ratio (area under curve of 0.977, P=0.000; cut-off value of 1.14［13.95%/12.24%］with a sensitivity of 93.3% and a specificity of 91.2%) showed good efficiencies in predicting GH (P<0.01). The mean and median of LTR of IBD patients who did not receive BA or surgical treatment weresignificantly longer (χ2=9.730, P=0.002; χ2=15.981, P=0.000). CD8+CD28+/CD8+CD28- ratio was significantly related to both BA (P=0.009) and surgery (P=0.038). Conclusion Both decreased CD8 + CD28 + T cells and elevated CD8 + CD28-T cells are closely correlated with GH, and their ratio can predict the occurrence of GH with a high sensitivity and specificity and is correlated with BA and surgery at the cut-off value of 1.14.