JAG1 is a Notch ligand that plays a critical role in multiple signaling pathways. However, the functionality of JAG1 in non-small cell lung cancer (NSCLC) has not been investigated thoroughly. By comparison of gene transcripted RNA profiles in the cell line pair with differential invasion ability, we identified JAG1 as a potential metastasis enhancer in lung cancer. Ectopic expression of JAG1 on lung cancer cells enhanced cell migration and invasion as well as metastasis in vitro and in vivo. Conversely, knockdown of JAG1 with siRNA in highly invasive cancer cells led to the reduction of migration and invasion. In clinical analysis, JAG1 mRNA expression was higher in tumors than in adjacent normal tissues in 14 of 20 patients with squamous cell carcinoma (SCC). SCC patients with higher JAG1 transcription had poor overall survival than those with low-transcripted JAG1. Microarray analysis indicated that the enforced JAG1 transcription was associated with an elevated HSPA2 RNA transcription, which played a role in promoting cancer cell migration and invasion. In conclusion, this is the first study that demonstrated that JAG1 might act as a potential prognostic marker and JAG1/HSPA2 axis mediates lung cancer malignancy at least partly.