Objective: To investigate the effect of microRNA-335 on the metastasis, invasion and proliferation of cells in patients with non-small-cell lung cancer (NSCLC). Methods:Real-time PCR was performed to detect the expression differences of microRNA-335 between 12 pairs of NSCLC and normal cancerous peripheral tissues, and between SPCA-1 cells of NSCLC and 16HBE of normal pulmonary epithelial cells, while miR-335 expression in SPCA-1 cells were down-regulated and proved by Lipofectamine 2000 transient transfection and real-time PCR, respectively. Scratch test, Transwell invasion assay as well as MTT and clone formation assays were applied to respectively determine the effect of miR-335 on the metastasis, invasion and proliferation of SPCA-1 cells. Results:Compared with para-carcinoma tissues and 16HBE cells, miR-335 expression was evidently higher in NSCLC and SPCA-1 cells. However, it decreased remarkably after transient transfection of anti-miR-335 by SPCA-1 cells with Lipofectamine 2000 for 24 h. Metastasis and invasion of SPCA-1 cells could be inhibited by suppressing miR-335 expression with suppression rates being (42.8±2.7)%and (73.25±4.4)%, respectively. However, the inhibition of miR-335 expression had no effect on the proliferation of SPCA-1 cells. Conclusion:miR-335 expresses highly in NSCLC and its low expression can obviously inhibit the metastasis and invasion of SPCA-1 cells, but has no effect on the proliferation.