Objective: To investigate the expression and significance of MNAT1 in non-small cell lung cancer (NSCLC) and to explore the biological impact of MNAT1 expression in lung cancer cells at the cellular level and related signaling pathway. Methods: Forty-eight cases of NSCLC tissues and paired normal tissues was collected at Nanfang Hospital, Southern Medical University from 2015 to 2017. The expression level of MNAT1 was detected by immunohistochemistry, and the relationship between MNAT1 and clinicopathological features was analyzed. The expression of MNAT1 was detected in lung cancer cells, MNAT1 level was analyzed after knocking down in A549 and H322 cells by siRNA; Plasmid vector of overexpressing MNAT1 was constructed, followed by transfecting H1299 cells and observing proliferation and migration at the cellular level. Flow cytometry was used to analyze the effect of the expression of MNAT1 on cell cycle, and Western blot was used to explore the possible molecular mechanism of MNAT1 on cell proliferation and cell cycle. Results: Immunohistochemistry showed that the expression score of MNAT1 was (4.07±3.55) in normal lung tissue and (7.33±4.09) in NSCLC tissue (P<P<P<P<Conclusions: MNAT1 may be involved in the development of non-small cell lung cancer.MNAT1 affects cell cycle and proliferation through the Akt/p21 pathway.