Objective:To investigate mRNA expression of human runt-related transcription factor1(Runx1) in non small cell lung cancer(NSCLC),and its genesis and development. Methods:The mRNA expression of Runx1 was measured by semi-quantitative RT-PCR in 37 cases of NSCLC tissues and 10 cases of normal tissues beside the lung benign lesion tissues. Results:The mRNA expression level of Runx1 gene was significantly lower in NSCLC tissues than in normal tissues(P < 0.01). The mRNA expression level of Runx1 gene was significantly related to lymphatic metastasis(P < 0.05). Conclusion:Compared with the control,the expression of Runx1 mRNA was dereased and was correlated with lymph node metastasis. It suggests that Runx1 should be involved in the generation and development of NSCLC.