BackgroundAt least 77.0% of breast cancer patients will experience cancer-related fatigue. Hope level and resilience play as two important factors that have influence on cancer-related fatigue. Currently， most studies involve one single factor， either the level of hope or resilience， and explore its relationship with the cancer-related fatigue. Only limited studies explore the action mechanism behind with all three factors put together. ObjectiveTo investigate the mediating role of resilience between hope and cancer-related fatigue in patients with breast cancer， and to provide references for finding intervention targets for cancer-related fatigue in breast cancer patients. MethodsFrom March to October 2022， this study was conducted on the sample size of 324 hospitalized patients from three Grade-A tertiary hospitals in Shaanxi Province. These patients were over 18 years old and pathologically diagnosed as breast cancer. Hope level， resilience and cancer-related fatigue were assessed， respectively， using Adult Dispositional Hope Scale （ADHS）， Connor-Davidson Resilience Scale （CD-RISC-10） and Cancer Fatigue Scale （CFS）. Pearson Correlation Analysis was used to analyze the relationship between ADHS score， CD-RISC-10 score and CFS score. AMOS 22.0 was used to analyze the mediating effect of resilience between hope level and cancer-related fatigue in breast cancer patients. ResultsThe detection rate of cancer-related fatigue in patients with breast cancer was 88.58%. Scores of ADHS and CD-RISC-10 were negatively correlated with CFS score （r=-0.750， -0.809， P<0.01）. ADHS score was positively correlated with CD-RISC-10 score （r=0.901， P<0.01）. Resilience had a mediating effect between the hope level and cancer-related fatigue. The mediating effect value was -0.676（95% CI： -1.005~-0.347）， accounting for 81.90% of the total effect. ConclusionThe hope level of breast cancer patients can affect cancer-related fatigue directly as well as indirectly through resilience. Resilience plays a partial mediating role between hope level and cancer-related fatigue .