The fusion gene between echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase(ALK) has recently been identified as a new molecular target of non-small cell lung cancers(NSCLC).The fusion gene has higher morbidity in NSCLC patients who are young , never or light smoking history and adenocarcinomas.This review emphasizes the biological,detection method,clinical characteristics and the therapeutic application of EML4-ALK in NSCLC.