Objective To evaluate the effectiveness and safety of radiosensitizer metronidazole amino acidum natrium (CMNa) for esophagus carcinoma. Methods Databases including The Cochrane library, PubMed, EMbase, CBM, CNKI, VIP and WanFang Data were searched from their establishment dates to Feb. 1st 2012 for randomized controlled trials (RCTs) of CMMa for esophagus carcinoma. Two reviewers independently screened literature and assessed the quality of the included studies and extracted data. Meta-analysis waw conducted using RevMan 5.1 software. Results A total of 17 RCTs involving 1 475 patients met the inclusion criteria. Results of meta-analyses showed that: a) As for short-term response, the total effectiveness of the experimental group given CMNa plus radiotherapy was higher than the control group given radiotherapy alone (OR=3.51, 95%CI 2.44 to 5.07, Plt;0.000 01). b) Significant differences were found in the quality of life, and one and two year survival rates (OR=2.90, 95%CI 1.91 to 4.39, Plt;0.000 01; OR=1.95, 95%CI 1.21 to 3.15, P=0.006). In accordance with the P-value of 0.05, there was a significant difference in three-year survival rate (OR=2.28, 95%CI 1.16 to 4.49, P=0.02). c) As for safety, no significant differences were found in radiation pneumonitis, radiation esophagitis, myelosuppression and mucous membrane reactions. Conclusion CMNa plus radiotherapy has beneficial effects in the treatment of esophagus carcinoma and improves 1, 2 and 3-year survival rates, but more RCTs on the quality of life and safety evaluation are needed.