中文摘要：

低空急流与强降水事件、空气污染、风能利用、航空安全、沙尘暴、森林火灾及其他诸多天气、气候现象存在着密切的联系，因此自发现之日起便受到人们的广泛关注。在过去的半个多世纪中，中外气象学家围绕着低空急流事件开展了大量的研究并取得了丰硕的研究成果。对这些成果进行了综合回顾，重点对低空急流的分类和定义、分布状况及结构特征，低空急流形成演变机制，低空急流与降水及其他领域的关系等三个方面的研究工作进行了总结。最后通过对比分析中外针对低空急流事件的研究历史和现状，指出了中国现有研究工作中所存在的诸如低空急流选取标准宽松、观测数据缺乏且质量控制不完善、低空急流自身特征与形成演变机制研究数量和深度有限、交叉领域研究工作匮乏等方面的问题，并对未来的研究方向进行了展望。

英文摘要：

The low-level jet （LLJ）is closely concerned with severe rainfall events,air pollution,wind energy utilization,avia-tion safety,sandstorms,forest fire,and other weather and climate phenomena.Therefore,it has attracted considerable atten-tion since its discovery.Scientists have carried out many studies on LLJs and made significant achievements during the past five or six decades.This article summarizes and assesses the current knowledge on this subject,and focuses in particular on three aspects：（1）LLJ definition,classification,distribution,and structure;（2）LLJ formation and evolutionary mechanisms;and （3）relationships between LLJ and precipitation,as well as other interdisciplinary fields.After comparing the status of LLJ re-searches in China with those abroad,we then discuss the shortcomings of LLJ research in China,which might cover the coarse definitions of the LLJ,lack of observations and inadequate quality control,few thorough explorations of LLJ characteristics and formation mechanisms,and limited studies in the light of interdisciplinary fields.The future prospects for several LLJ research avenues are also speculated.