Abstract: Objective To explore the expression of miRNA-769-5p （miR-769-5p） in non-small cell lung cancer（NSCLC）and its effect on proliferation， migration and invasion of NSCLC cells.Methods The miR-769-5p expression in NSCLC cell lines （A549， NCI-H1299， NCI-H157， ANIP-973 and GLC-82） was detected by QRT-PCR， and the cell lines of highest and lowest expression of miR-769-5p were applied for the further study. NSCLC cell lines were divided into transfection group and control group， and respectively transfected with miR-769-5p mimics／inhibitor and miRNA mimics control／inhibitor control. Furthermore， cell proliferation， colony formation migration and invasion were respectively analyzed by MST， colony formation， and transwell chamber experiments. Results The expression of miR-769-5p in A549， NCI-H1299， NCI-H157， ANIP-973 and GLC-82 were 0.06， 0.40， 0.09， 1.04 and 2.31. miR-769-5p mimics and miR-769-5p inhibitor were respectively transfected into A549 and GLC-82 cell lines. MST test showed that transfection with miR-769-5p mimics in A549 cells for 48， 72， 96 h significantly inhibited the cell viability （P＜0.05）. The colony formation （124.7±14.7 vs. 399.4±46.0，P＜0.05）， migration （94.4±18.1 vs. 157.8±24.8， P＜0.05） and invasion （84.4±15.1 vs. 135.6±16.7，P＜0.05） ability of A549 cell were also suppressed compared with control group after transfection. Down-regulation of miR-769-5p by transfected with miR-769-5p inhibitor could enhance the malignant phenotype of GLC-82 cells in vitro， including cell growth （P＜0.05）， colony formation （555.7±29.7 vs. 366.3±28.7，P＜0.05）， as well as cell migration （226.7±40.3 vs. 153.3±38.7，P＜0.05） and invasion （196.7±39.1 vs. 138.9±40.4，P＜0.05）. Conclusion The expression of miR-769-5p can inhibit the proliferation， migration and invasion of NSCLC cells.