Abstract: Objective To investigate the expression and clinical significance of miR-449a／b／c in non-small cell lung cancer（NSCLC）as well as their expressions with prognosis. Methods We collected 82 cases of surgically resected NSCLC tissues and 69 cases of adjacent normal tissue（＞5 cm away from cancer tissue）from January 2013 to December 2015. The expressions of miR-449a/b/c of above tissues were detected by using real-time fluorescence quantitative PCR （QPCR）. The differences of distribution of miR-449a/b/c expressions in NSCLC and adjacent normal tissues were compared. Pearson correlation analysis of miR-449a，miR-449b and miR-449c in NSCLC tissues was undergone. The relationship of miR-449a/b/c expressions in NSCLC with clinical pathological parameters（gender，age，tumor size，TNM stage，histological type and lymph node metastasis）were analyzed. According to the follow-up data，the prognosis of different expressions of miR-449a/b/c was compared. Results QPCR results showed that in NSCLC tissues， the avarage expressions of miR-449a，miR-449b and miR-449c were 0.210±0.028，0.359±0.031 and 0.133±0.020，lower than those in adjacent normal tissues，and the differences were statistically significant （P＜0.05）. The expressions of miR449a，miR-449b and miR449c were positively correlated in NSCLC and correlation coefficients for miR-449a/b， miR-449a/c and miR-449b/c were 0.246，0.390 and 0.331 （P＜0.05）. The miR-449a/b/c levels of NSCLC tissues were significantly associated with TNM stage，and miR-449a and miR-449c were related to tumor size. All patients were followed up，and the median overall survival（OS）was 12.4 months. The median OS for miR-449a low expression group and high expression group were 11.2 and 13.5 months （P＞0.05）. The median OS for miR-449b low expression group and high expression group were 9.6 and 14.2 months （P＜0.05）. The median OS for miR-449c low expression group and high expression group were 11.7 and 13.7 months（P＞0.05）. Conclusion The expression of miR-449a/b/c in NSCLC tissues was decreased，and all of them were related to TNM stage. The expression of miR-449b was related to prognosis，which may be related to the occurrence and development of NSCLC. It has some value in the diagnosis and evaluation of NSCLC.