Long noncoding RNAs (lncRNAs),contraining more than 200 nucleotides,are RNA transcripts without protein-coding capacity.It has been reported that lncRNAs regulate gene expression at the epigenetic,transcriptional and post-transcriptional levels,and are deeply involved in various biological processes.Many diseases are found related to lncRNAs and they have become a focus of studies.According to recent evidences,a number of lncRNAs are changed in lung cancer,and they play a significant part in the development,progression and prognosis of lung cancer.This review focuses on the definition and functional mechanism of lncRNAs and their relation with lung cancer.