Abstract: Objective :To explore the clinical and pathological diagnosis and differential diagnosisof synovial sarcoma. Methods :Forty-one paraffin-embedded synovial sarcoma samples were collected,and routine histochemistry staining, immunohistochemistry and reverse transcription-polymerase chainreaction (RT-PCR) were used to study the clinical and pathological features. Results :Twelve caseswere the biphasic type,22 cases were the monophasic fibrous type, and 7 cases were a poorlydifferentiated type. Thirty-six cases were both CK (and/or EMA) and Vim positive. Only 5 cases wereVim positive.The SYT-SSX fusion gene was detected in 18 of 20 (90%) cases by RT-PCR. Conclusion :The diagnosis of synovial sarcoma can be based on histomorphologic observation,immunohistochemistry staining and detection of the fusion gene SYT-SSX.