Abstract: Objective：To analyze the clinical and pathological features of cardiac synovial sarcoma, aiming to improve the understanding of cardiac synovial sarcoma. Methods：Three patients with cardiac synovial sarcoma admitted to Zhongshan Hospital, Fudan University were selected in the resent years. The clinical data, pathological features, treatment and follow-up data of the 3 cases were retrospectively analyzed, and combined with reports of cardiac synovial sarcoma for clinical pathological typing, immunohistochemistry, and genetic testing. Results：The pathological types of 2 cases of synovial sarcoma were spindle cell type, with the cells were short spindle type and moderately atypical. One case was biphasic type synovial sarcoma,with the cells formed adenoid structure and were mixed with the spindle cells. Conclusions：synovial sarcoma is a very rare soft tissue malignant tumor, especially in the heart. The diagnosis should be comprehensively made according to tissue morphology, immunohistochemical staining, and SYT gene status, and be differentiated from other soft tissue tumors.