Abstract: Worldwide,non-small cell lung cancer(NSCLC)is one of the leading causes of cancer-related death.With the development of the knowledge about the molecular pathogenesis underling NSCLC,we can find new targets and anticancer agents,and novel strategies of targeted therapys for the patients with NSCLC.The polo-like kinase1(PLK1)is a serine/threonine of kinase and it is a key regulator of mitosis.The inhibition of PLK1 can lead to mitotic arrest and tumor cell apoptosis.PLK1 is overexpressed in the tissue of tumor,however,it is hardly detected in most adult tissue.RNA interference(RNAi)is another powerful tool which can target mRNA and reduce the expression of the targeted gene.In this review,we will focus on the PLK1,and discuss the studies of PLK1 inhibitors and siRNA against PLK1,with special emphasises on NSCLC.