Objective To analyze and validate the risk factors of catheter-related bloodstream infections（CRBSI） in infusion ports implanted in patients with gastrointestinal tumors, and to provide references for intervention strategies. Methods A total of 573 gastrointestinal cancer patients with an infusion port implantation for chemotherapy were retrospectively enrolled and served as the derivative group, whose CRBSI rate was calculated. Then through univariate and multivariate Logistic regression analysis, the risk factors of CRBSI were identified, and used to build up a nomogram prediction model in R software.Another 201 patients were prospectively enrolled and served as the validation group for external verification, in which, the validity of the nomogram prediction model was validated. Results The incidence rate of CRBSI was 10.82% in the derivative group, and 12.94% in the validation group.Multivariate Logistic regression analysis showed that KPS score ≤60 points, use of parenteral nutrition, diabetes history, and single use time of butterfly needle were independent risk factors of CRBSI in the infusion port （P＜0.01 for all）.The CRBSI nomogram prediction model was constructed based on the selected risk factors, and subjected to internal and external validation respectively, with the former yielding a result of 0.865, and the latter 0.775, for the area under the ROC curve. Conclusion The risk factors of CRBSI in the infusion portare associated with patients′ health status, use of parenteral nutrition, diabetes history, and single use time of butterfly needle.The CRBSI nomogram prediction model constructed based on the risk factors enjoys good predictive efficacy.Medical staff should beef up intervention targeting the risk factors, in an effort to prevent the occurrence of CRBSI.