Objective: To investigate the value of peripheral blood Mucin 1 (MUC1) mRNA and cytokeratin 19 fragment (cyfra21-1) in diagnosis of non-small cell lung carcinoma (NSCLC). Methods: Eighty patients with NSCLC (NSCLC group), 50 patients with benign pulmonary disease (benign group) and 40 healthy cases (healthy group) were enrolled in this study. e levels of MUC1 mRNA and cyfra21-1 were detected. e values of MUC1 mRNA and cyfra21-1 in diagnosis of NSCLC were analyzed. e di erences of MUC1 mRNA and cyfra21-1 positive rate were compared in patients with di erent pathological features. Results: e levels of MUC1 mRNA and cyfra21-1 in NSCLC group were signi cantly higher than those in the benign group and the healthy group (P<0.05); while there was no significant difference in levels of MUC1 mRNA and cyfra21-1 between the benign group and the healthy group (P>0.05). The best cut-off value of MUC1 mRNA in diagnosis of NSCLC was MUC1 mRNA >2.14 with the sensitivity was 68.8% and speci city was 94.4%. e best cut-o value of cyfra21-1 was cyfra21-1 >3.20 ng/mL with the sensitivity was 75.0% and speci city was 98.9%. e sensitivity of joint application of MUC1 mRNA and cyfra21-1 was 87.5%, which was signi cantly higher than that of MUC1 mRNA or cyfra21-1 alone (P<0.05), while there was no signi cant di erence in speci city (P>0.05). e positive rates of MUC1 mRNA and cyfra21-1 were signi cantly correlated with tumor size, di erentiated degree, TNM staging, and lymph node metastasis (P<0.05), but no correlated with age, gender and histologic type (P>0.05). Conclusion: e detections of MUC1 mRNA and cyfra21-1 are helpful in clinical diagnosis and disease evaluation of NSCLC.