Objective:To understand the current status of health-related hardiness among breast cancer patients undergoing radiotherapy and to analyze its influencing factors, and to provide evidence for the development of psychosocial care programs for breast cancer patients undergoing radiotherapy.Methods:A total of 126 postoperative breast cancer patients undergoing radiotherapy were selected from the First Affiliated Hospital of Dalian Medical University from January to September 2018. The self-designed general data questionnaire and Health-related Hardiness Scale (HRHS) were used to analyze the current status and the influencing factors of health-related hardiness among patients.Results:The overall score of health-related hardiness among breast cancer patients undergoing radiotherapy was 127.61±20.19, which was located at the low medium level. There were significant differences in the scores of patients of different ages, education background, marital status, fertility status, children status, family history, religion, family income, and medical insurance forms ( t value was -3.800-8.128, F value was 8.906-274.271 P<0.01). The regression analysis showed that the influencing factors of health-related hardiness were age, family income, marital status, education background, family history, and religion. The degree of the dependent variable was 89.4%. Conclusions:Breast cancer patients undergoing radiotherapy have a low medium level of health-related hardiness, and are affected by age, family income, marital status, education background, family history, and religion.