外泌体是一种几乎所有细胞都能分泌的胞外小泡，在细胞和器官之间运输脂质、蛋白质和核酸。作为一种天然细胞间通信器，外泌体广泛分布在生物体液中。外泌体中的微小RNA(miRNA)在肿瘤的发生、发展和侵袭转移中起至关重要的作用，并具有成为肿瘤生物标志物的潜力。本文综述了外泌体中miRNA在肺癌诊断、预后评估及药物疗效预测中的作用，并总结其面临的挑战。“,”Exosomes are extracellular vesicles that can be secreted by almost all cells, transporting lipids, proteins and nucleic acids between cells and organs.As a natural intercellular communicator, exosomes are widely distributed in biological body fluids.MicroRNA (miRNA) in exosome play an important role in the occurrence, development, invasion and metastasis of tumor, and they have great potential as a non-invasive biomarker for tumor diagnosis.This article reviews the role of miRNA in exosome in the diagnosis, prognosis and drug efficacy prediction of lung cancer, and summarizes the challenges.