The purpose of this study is to confirm the difference of Capecitabine plus with or without oxaliplatin over cisplatin plus 5-fluorouracil with definitive chemoradiotherapy for esophagus squamous cell carcinoma. A total of 630 patients will be accrued from China within 2 years. The primary endpoint is overall survival and the secondary endpoints include progression-free survival, response rate, pathologic complete response rate and adverse events.