Objective: To explore the diagnostic value of serum cell-free DNA (cfDNA) concentration and integrity for esophageal carcinoma. Methods: Venous blood samples from 68 patients with esophageal cancer, 36 patients with benign esophageal lesions and 45 healthy subjects were collected. Circulating cfDNA was verified through quantitative real-time PCR (Alu-qPCR) using Alu-115 and Alu-247 primers. DNA integrity index was calculated as the ratio of Alu-qPCR results (Alu247/115). Concentrations of carcino-embryonic antigen (CEA) and squamous cell carcinoma associated antigen (SCC) were detected by chemiluminescence analyzer assay. Statistical analysis was performed using Mann-Whitney U test, Kruskal-Wallis H test and Spearman correlation test. The Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficiency of each index to esophageal carcinoma. Results: The median absolute serum Alu115 and the Alu247/115 index (1 162.0 ng/ml, 0.57) in esophageal cancer group were significantly higher than those in benign esophageal disease group (496.7 ng/ml, 0.43) and in healthy control group (432.3 ng/ml, 0.42) (all P<0.01, respectively). The Alu115 and Alu247/115 index of serum DNA in benign esophageal disease group were no statistically different from those in the healthy control group (all P>0.05, respectively). The levels of cfDNA and its integrity were not significantly correlated with age, gender, tumor differentiation, or disease stage according to American Joint Committee on Cancer (AJCC) staging system in the esophageal cancer group (all P>0.05). The serum Alu247/115 index of Stage Ⅲ patients was higher than that of Stage Ⅰ~Ⅱ patients(P<0.05). The serum Alu247/115 index of Stage Ⅳ was higher than that of Stage Ⅲ(P<0.05). In the esophageal cancer group, both of serum Alu115 and Alu247/115 index had no correlation with CEA or SCC (all P>0.05). The area under the ROC curve (AUC) of Alu115 and Alu247/115 index were 0.867 and 0.854, respectively, which were both higher than that of CEA (0.622) and SCC (0.753). The addition of Alu115 or Alu247/115 index to CEA and SCC detection increased the sensitivity of the diagnosis of esophageal cancer by 95.6% and 94.1%, respectively. Conclusions The detection of serum cfDNA concentration and integrity is helpful to the early diagnosis and monitoring of esophageal cancer. Their diagnostic value of esophageal cancer is better than that of the traditional tumor markers CEA and SCC.