New potential biomarkers and therapeutic targets for ovarian cancer should be identified. The amplification in chromosomal region 5q31-5q35.3 exhibits the strongest correlation with overall survival (OS) of ovarian cancer. SOX30 coincidentally located at this chromosomal region has been determined as a new important tumor-suppressor. However, the prognostic value, role and mechanism of SOX30 in ovarian cancer are unexplored. Here, we revea1 that SOX30 is frequently over-expressed in ovarian cancer tissues, and is associated with clinical-stage and metastasis of ovarian cancer patients. High SOX30 expression predicts better OS and acts as an independent prognostic factor in advanced-stage patients, but is not associated with OS in early-stage patients. Based on the survival analyses, the advanced-stage patients with high SOX30 expression can receive the platin and/or taxol based chemotherapy, whereas should not receive chemotherapy containing gemcitabine or topotecan. Functionally, SOX30 strongly inhibits tumor cell migration and invasion in intro, and suppresses tumor metastasis in vivo. SOX30 regulates markers (E-cadherin, Fibronectin, N-cadherin and Vimentin) and prevents the characteristics of epithelial-mesenchymal transition (EMT). SOX30 transcriptionally regulates the expression of E-cadherin, Fibronectin and N-cadherin by binding to their promoters. Restoration of E-cadherin and/or N-cadherin when over-expressing SOX30 significantly reduces the anti-metastatic role of SOX30. Indeed, chemotherapy treatment containing platin or gemcitabine combined with SOX30 expression influences tumor cell metastasis and the survival of nude mice differently, which is closely associated with EMT. In conclusion, SOX30 antagonizes tumor metastasis via preventing EMT process that can be used to predict survival and incorporated into chemotherapeutics of advanced-stage ovarian cancer patients.