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本文对关于街谷内空气流动及污染物扩散的研究进行评述.通过街谷物理模型及边界条件的分析.揭示影响街谷内空气流动与污染物扩散的物理因素.为进一步的数值预报模式的研究和数值模拟精度的提高提供思路.本文发现街谷几何结构和变化的背景风速、风向是影响街谷内空气流动与污染物扩散的主要因素.而街谷内大气稳定度和行驶车辆诱导湍流能很大程度影响街谷内的湍流强度和污染物分布.尤其在弱风环境下.在有绿化树木存在的街谷内绿化树木的影响也不容忽视.目前的经验、半经验模式对街谷模型真实性因素和气象条件考虑不够,造成模拟、预报结果误差较大.未来数值模式的发展重点在基于CFD的综合模式开发,并充分考虑街谷模型真实性因素和气象条件的影响. “,”This work gives a review of studies on air flow and pollutant dispersion in urban street canyons. Affecting factors on air flow and pollutant dispersions in urban street canyons are revealed by analyzing the street canyon physical model and boundary conditions, which will provide new scopes for the studies of numerical forecasting model and for improvements of simulation accuracies. Former studies show that, the building layouts along the street and the variations of the ambient wind velocities and directions are the main factor affecting on air flow and pollutant dispersion inside urban street canyons, while the atmospheric instabilities inside the street canyons and the vehicle induced turbulence are main impact factors on turbulent characters and pollutant distributions inside the street canyons, especially under weak-wind conditions. Incase the street canyons with tree plantings, effects of tree plantings on air flow and pollutant dispersions are can not neglected. The current empirical or semi-empirical models are lacking in fully considering of the canyon real geometries and atmospheric conditions, resulting in the simulated or forecasted results with large errors. Further developing of numerical model should focus on the integration models that based on the Computational Fluid Dynamic (CFD) method, with the real geometries of the canyons and atmospheric conditions are fully considered.