Abstract: Objective:To examine the expression of Twist and Snail, two key transcriptional regulators of epithelial-mes -enchymal transition (EMT) and tumor metastasis, in synovial sarcoma(SS) tissue and to investigate their impact on distant metastasis and prognostic value in patients with SS. Methods:Histopathological and immunohistochemical staining were performed to evaluate the expression of Twist and Snail in tissue specimens from133 patients with SS in Tianjin Cancer Hospital between January 1973 and January 2005. In addition, clinicopathologic characteristics and survival were com-pared with the expression of Twist and Snail using statistical software SPSS13.0. Results: Twist and Snail were located in the cytoplasm and/or nucleus in SS tissue. The expression of Twist was related with histological subtype (P = 0.002 ), AJCC stage (P = 0.045 ) and syt-ssx ( P = 0.000 ). The expression of Snail was related with histological subtype only (P = 0.006 ). Twist expression was corvelated with that of Snail ( r s = 0.191 , P = 0.027 ). Log Rank test showed that patients with high ex -pression of Twist and Snail had shorter survival than those with low expression (P = 0.03) and the expression of Twist and Snail was related with shorter metastasis-free survival ( P = 0.001 and P = 0.032 ). Conclusion: These results demonstrate that the high expression of Twist and Snail exist in patients with SS and may play an important role in the EMT and metasta -sis of SS. Twist and Snail may play a role in regulating the EMT of SS and their co-expression suggests poor prognosis. Evaluation of Twist and Snail expression is helpful for evaluating metastasis and prognosis of patients with SS.