Objective To identify the level and determinants of social frailty in older patients with heart failure (HF), and to provide references for targeted intervention.Methods A total of 427 hospitalized older HF patients were surveyed using a general information questionnaire, the Social Vulnerability Index, the FRAIL Scale, the Mini-mental State Examination, the Barthel Index, the Mini-Nutrition Assessment Special for Heart Failure and the Patient Health Questionnaire.Results The median (P25-P75) score of social frailty was 13.50（9.50,17.50）. Multiple linear regression analysis showed that age, education level, marital status, monthly household per capita income, place of residence, mode of residence, exercise frequency, course of disease, cognitive dysfunction, frailty, the ability to perform activities of daily living, and nutritional status were factors affecting social frailty （all P＜0.05）, which explained 64.4% of the variance.Conclusion Social frailty is common among older HF patients, and is at high level.Medical staff should strengthen assessments, pay close attention to vulnerable patients, and develop personalized intervention strategies, to prevent or delay the occurrence and development of social frailty.