Abstract: Objective To investigate the frequency of aberrant methylation of Reprimo and 14-3-3 Σ in non-small cell lung cancer (NSCLC). Methods Aberrant methylation of Reprimo and 14-3-3 Σ were examined by methylation specific-PCR (MSP) in primary NSCLC and normal lung tissues (n = 60). Results Aberrant methylation of Reprimo and 14-3-3 Σ were found to be present in 36.67％ and 28.33% of all NSCLC patients respectively.Three cases of Aberrant methylation of Reprimo(5%) and 4 cases of 14-3-3 Σ(6.67%) were detected in normal lung tissues. The frequencies of aberrant methylation of Reprimo and 14-3-3 Σ between primary NSCLC and normal lung tissue group were significantly different. Aberrant methylation of Reprimo was more frequently observed in older patients group (P=0.047) and smoking group (P=0.038). There was no significant correlation between Reprimo methylation frequencies and sex, pathology type, clinical staging and lymphatic metastasis. Similarly no significant association was found between 14-3-3 Σ methylation frequencies and sex, age, pathology type, clinical staging, smoking habit and lymphatic metastasis. Conclusion Methylation of Reprimo and 14-3-3 Σ may play an important role in the pathogenesis of NSCLC.