Background: CRT with 5- FU and cisplatin (PF) has shown greater clinical efficacy for local advanced esophageal cancer (EC) but with high rate of acute toxicities (ATs). CRTCOESC is a randomized, open-label, multicenter trial designed to evaluate the effect and safety of capecitabine with or without oxaliplatin versus PF with CRT in Chinese EC. Methods: Pts with biopsy-proven squamous EC (T2-4N0-2M0) were randomized to single capecitabine (Arm1), capecitabine plus oxaliplatin (Arm2), or PF (Arm3), while daily radiation 50Gy/2Gy for all. Pts were stratified by different regimens cycles. Both grade3-5 ATs and 2-year OS were the primary endpoint, with a planned accrual of 249 pts to detect a decrease in Grade3-5 ATs from 40% to 20%. The secondary endpoint included objective response rate (ORR) and 2-year progression free survival (PFS). Interim analysis of ATs and ORR was planned for the first 120 pts. Results: The study accrued 128 pts from 2014.10-2016.12, 118 were eligible. 86 patients were finished 16-weeks follow-up at least and analyzed in the interim report (Arm1: Arm2: Arm3 = 24: 37: 25). There was no difference between three arms on pts pretreatment characters (age, gender, weight, performance status, clinical stage, lymphonodus status, and pathology grade). Incidence of grade3-5 ATs in Arm1/2/3 were 25%: 32.4%: 64% (p = 0.03); it was significantly lower in Arm1/2 than Arm3 (Arm1 vs Arm3, p = 0.041; Arm2 vs Arm3, p = 0.022); and there no meaningful different between Arm1 and Arm2 (p = 0.738). The pCR rate and ORR were 50%: 48.6%: 48% and 87.5%: 83.8%: 100% in Arm1/2/3 (p = 0.99; p = 0.133). 56 patients had been finished 1 year follow-up (Arm1: Arm2: Arm3 = 12: 26: 18). The 1-year OS and PFS were 75%: 91.9%: 76% and 66.7%: 62.2%: 60% in Arm1/2/3 (p = 0.166; p= 0.926). Conclusions: Compared with PF, CRT with single capecitabine with or without oxaliplatin shown lower incidence of ATs and similar ORR and 1-year OS. The single capecitabine seemly carried out a benefit of lower ATs than it plus oxaliplatin; there was no meaningful difference for them on ORR and 1-year OS. Ruinuo Jia and Tanyou Shan did equal work. Clinical trial information: NCT02025036