Objective To investigate the status of preparatory grief among breast cancer patients undergoing chemotherapy, and to analyze its influencing factors, so as to provide reference for clinical medical staff taking effective interventions. Methods A total of 196 breast cancer patients undergoing chemotherapy were selected using convenience sampling method, then they were investigated utilizing the general information questionnaire and the Preparatory Grief in Advanced Cancer Patients scale (PGAC). Results The total PGAC score of the breast cancer patients was (35.26±16.97). The univariate analysis showed that, the patients with different places of residence, educational backgrounds, occupations, personal monthly income, self-perceived psychological status, fatigue, insomnia, loss of appetite, movement disturbance and duration of illness scored significantly different in PGAC (P<0.05, P<0.01). And multivariate analysis indicated that, personal monthly income, self-perceived psychological status, fatigue and movement disturbance were the major influencing factors of preparatory grief among breast cancer patients undergoing chemotherapy (P<0.05, P<0.01), which explained 24.60% of the total variance. Conclusion Preparatory grief among breast cancer patients undergoing chemotherapy is at a medium level. Medical staff should pay attention to their mental health status, assess and analyze the influencing factors of preparatory grief, then develop individua-lized intervention plan to reduce their preparatory grief.