Objective:To understand the current status of the compliance of immunosuppressive drugs in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT) and to explore the influencing factors of their compliance.Methods:This study was a cross-sectional study. Using the convenient sampling method, a total of 238 allo-HSCT patients who were followed up in the Transplant Center of Taizhou Hospital of Zhejiang Province, Zhejiang Provincial Hospital of Traditional Chinese Medicine and the First Affiliated Hospital of Wenzhou Medical University from March 2020 to February 2021 were selected as the research objects. The self-designed general information questionnaire, Basel Assessment Scale for Immunosuppressive Drug Compliance, Chinese version of Medication Belief-Specific Scale, General Self-Efficacy Scale, Perceived Social Support Scale and Family Care Index Scale were used for on-site investigation of patients. Pearson correlation analysis was used to analyze the correlation between medication compliance and medication belief, self-efficacy, social support and family care of allo-HSCT patients. Multiple linear regression analysis was used to investigate the influencing factors of immunosuppressive medication compliance in allo-HSCT patients.Results:A total of 238 questionnaires were distributed in this study, and 228 valid questionnaires were finally recovered. The medication compliance score of allo-HSCT patients was (4.80±1.18) points. And 111 patients (48.68%, 111/228) had poor medication compliance, among which the incidence of not taking medication on time was the highest, accounting for 44.30% (101/238) . Multiple linear regression analysis showed that average monthly family income, rejection, medication belief, social support and family care were the influencing factors of medication compliance ( P< 0.05) . Conclusions:The immunosuppressant medication compliance of allo-HSCT patients is at a medium and low level. Average monthly family income, rejection reaction, medication belief, social support and family care are the main factors affecting the immunosuppressant medication compliance of allo-HSCT patients. Medical staff should formulate targeted intervention measures according to the influencing factors of medication compliance to improve the immunosuppressive medication compliance of allo-HSCT patients.