Abstract: Objective : To detect the expression of CK20 mRNA and hTERT mRNA in peripheral blood of gastric car-cinoma patients and to discuss whether these levels can be used as molecular biological markers for predict-ing micrometastasis and evaluating prognosis. Methods : Peripheral blood samples of 40 patients with gastriccarcinoma, 19 patients with benign gastric lesions, and 20 healthy cases were assessed by RT-PCR for quali-tative and semi-quantitative analysis of CK20 mRNA and hTERT mRNA. Results : (1) The positive rate ofCK20 mRNA and hTERT mRNA in gastric carcinoma patients was 52.50% and 65.00% and the related coeffi-cients were 0.81±0.17 and 0.78±0.17, respectively. The positive rate of CK20 mRNA and hTERT mRNA in pa-tients with benign gastric lesions was 5.26% and the related coefficients were 0.12 and 0.11. The two markerswere not found in samples from healthy people. Significant differences were found in the expression of CK20mRNA and hTERT mRNA in peripheral blood among patients with benign gastric lesions, patients with gastriccarcinoma, and healthy people (P<0.01). (2) The positive rates and related coefficients of CK20 mRNA andhTERT mRNA were significantly correlated with clinical stage, lymph node metastasis, and distant metastasis(P<0.05). The patients with expression of CK20 mRNA and hTERT mRNA had lower survival rates comparedwith those without expression of CK20 mRNA and hTERT mRNA (P<0.05). Conclusion : CK20 mRNA andhTERT mRNA were detected in peripheral blood of gastric carcinoma patients. The two markers can be usedto predict micrometastasis and evaluate prognosis because they are closely correlated with clinical stage andsurvival.