Objective To investigate the risk factors of syncope symptom in patients with pulmonary embolism (PE).Methods 457 patients with confirmed pulmonary embolism were recruited in the study.They were divided into two groups:the syncope group (44 patients) and the group without syncope (413 patients).The clinical manifestation,laboratory examination,physical examination,imagingof all patients were analyzed by unconditional logistic regression.Results (1) Single factor analysis,prevalence of syncope was 9.6％ (44/457) in these patients with PE.Those with syncope had some higher risk factors,including age over 60,coronary heart disease,hypertension,stroke and lower limb vein thrombosis history.The proportion of falling pressure chest painand centricity thrombus in syncope group were increasing compared with the groupwithout syncope.Pulmonary embolism severity index (sPESI) score was higher than groupwithout syncope.(2) Multivariate analysis showed that hypertension coronary heart disease and Centricity thrombus were the independent correlates of the presence of syncope in the patients with PE.Conclusions Patients who had histories of hypertension and coronary heart disease may have the higher risk factors of syncope.Blood pressure falling and central localization may be more likely to happen in PE patients with syncope.