Abstract: Objective: To investigate the expression change, biological role and action mechanism of long non-coding RNA (lncRNA) LINC00978 in non-small cell lung cancer (NSCLC). Methods: The expression levels of LINC00978 in tumor tissues and serum samples of NSCLC patients were detected by the qRT-PCR. The effects of knockdown and overexpression of LINC00978 on the biological function of A549 cells were determined by the CCK-8, colony formation, Transwell migration and invasion assays. The action mechanisms of LINC00978 in NSCLC were investigated by the flow cytometry, qRT-PCR and western blot, respectively. Results: The expression levels of LINC00978 in the tissues ( t =2.465, P ＜0.05) and serum samples ( t =8.781, P ＜0.01) of NSCLC patients increased. The knockdown of LINC00978 inhibited the proliferation, migration and invasion of A549 cells ( P ＜0.01) and induced cell cycle arrest at G1 phase and apoptosis of A549 cells ( P ＜0.01). The knockdown of LINC00978 downregulated the expression of Cyclin D1 and Bcl-2 , and upregulated the expression of Bax ( P ＜0.05). In addition, the knockdown of LINC00978 inhibited the expression of N-cadherin, Vimentin, Snail, Slug and Twist, and promoted the expression of E-cadherin ( P ＜0.05). The overexpression of LINC00978 had the opposite effect. Conclusion: LINC00978 is highly expressed in NSCLC and can promote the occurrence and progression of NSCLC, which may serve as a potential target for the diagnosis and therapy of NSCLC.