Non-Small Cell Lung Cancer (N-SCLC) accounts for almost 85% of all diagnosed lung cancer and the prognosis remains poor usually because of assimilated drug resistance including cisplatin. The miR-497-5p family has been discovered to play a significant role in regulating biological functions in N-SCLC. The purpose of this study was to investigate the molecular mechanism of miR-497-5p and its target gene on modulating cisplatin chemosensitivity in N-SCLC cells. The enhanced chemosensitivity effect of miR-497-5p to cisplatin in A549 and H1299 cells was detected by MTT method. Dual luciferase reporter assay, quantitative Real-Time PCR (qRT-PCR) and Western blotting were performed to demonstrate that miR-497-5p directly targets CDCA4 to reduce the expression. Transwell, colony formation and flow cytometry assays showed that combination of miR-497-5p and cisplatin exerted stronger effects on inhibiting N-SCLC cells proliferation, migration and invasion as well as promoting apoptosis and G1 phase arrest than miR-497-5p and cisplatin alone. The same tendency was observed in the upregulation of apoptosis-related protein Bax and Cytochrome-C and downregulation of cycle-related proteins CyclinB1 and CDK1. Our results indicate that upregulation of miR-497-5p targets CDCA4 directly and may function as an important modifier to sensitize N-SCLC cells to cisplatin.