Lung cancer is one of the most common types of tumors and the leading cause of cancer-associated mortality in the world. Additionally， non-small cell lung cancer (NSCLC) accounts for ~80% of all lung cancer cases. Epithelial-mesenchymal transition (EMT) is an important cell biological process， which is associated with cancer migration， metastasis， asthma and fibrosis in the lung. In the present study， it was revealed that miR-145-5p was able to suppress EMT by inactivating the c-Jun N-terminal kinase (JNK) signaling pathway in NSCLC cells. Mitogen-activated protein kinase kinase kinase 1 (MAP3K1) was predicted and confirmed to be a novel target of miR-145-5p. Overexpression of MAP3K1 was able to reverse the inhibition of EMT induced by miR-145-5p via the JNK signaling pathway. Overall， the results revealed that miR-145-5p inhibits EMT via the JNK signaling pathway by targeting MAP3K1 in NSCLC cells.