Abstract：Objective：To study the influencing factors of cancer-related fatigue （CRF） in breast cancer patients and analyze its correlation with traditional Chinese medicine （TCM） constitution types. Methods：A total of 312 breast cancer patients treated in Taizhou Hospital of Zhejiang Province from May 2024 to August 2025 were enrolled. Demographic characteristics，clinical data，and laboratory indicators were collected. The Revised Piper Fatigue Scale was adopted to evaluate the severity of fatigue，and the TCM Constitution Classification and Determination Self-rating Scale was used to identify TCM constitution types. The influencing factors of CRF and its correlation with TCM constitution types were statistically analyzed. Results：A total of 303 valid questionnaires were finally included in the statistical analysis. Univariate analysis showed that age， disease duration， tumor stage， molecular subtype of breast cancer，targeted therapy，endocrine therapy，red blood cell count，hemoglobin，albumin，as well as qi deficiency constitution，qi stagnation constitution，yin deficiency constitution，yang deficiency constitution，and phlegm-damp constitution were significantly correlated with the degree of CRF in breast cancer patients， differences being significant （P＜0.05）. Binary logistic regression analysis indicated that age，disease duration，tumor stage，molecular subtype of breast cancer， albumin level， qi deficiency constitution， qi stagnation constitution， yin deficiency constitution， yang deficiency constitution， and phlegm-damp constitution were independent influencing factors for CRF （P＜0.05）. Conclusion： TCM constitution identification can early screen high-risk groups of CRF in breast cancer patients. Early intervention based on constitution differentiation can effectively improve patients′ quality of life.