Objective To investigate the expressions and clinical significances of MUC1-mRNA and CK20-mRNA in peripheral blood of esophageal cancer patients.Methods MUC1-mRNA and CK20-mRNA were detected in 53 patients with esophageal cancer,10 patients with esophageal benign tumor and 20 healthy volunteers by RT-PCR technique.Results The expressions of MUC1-mRNA,CK20-mRNA and combining group were 35.85 % (19/53),49.06 % (26/53) and 62.26 % (36/53) in peripheral blood of 53 esophageal cancer patients.In control group,there was no expression of MUC1-mRNA and CK20-mRNA in peripheral blood of 10 patients with benign esophageal disease and 20 healthy volunteers.The positive rate increased by combining test(x2 =11.0228,P ＜0.05).Conclusion MUC1-mRNA and CK20-mRNA might be specific and sensitive markers to detect circulating tumor cells in peripheral blood and their expressions are closely related to TNM stages of the esophageal cancer patients.The combining test might be of high value of the diagnosis of micrometastasis.