||Meteorological impacts on air pollutant transport in highly urbanized region were investigated using the mesoscale meteorological models and air quality model. Two meteorological impacts were examined in this thesis. One was the impact of layer collapsing on O3 transport during strong lanf sea breeze circulation (LSBC), the other was the mechanical impact of building availability on PM10 transport. In order to alleviate the computational cost of air quality modeling for chemical process calculation associated with a large number of vertical layers, the vertical layer collapsing technique is widely used to reduce the height number of vertical layers. A relatively fine resolution in the troposphere is preserved as in the meteorological model and a coarser resolution above 2.0 km results from layer collapsing. In general, this action is thought to have an insignificant impact on ozone ground-level concentration. However, through the off-line coupling of the Fifth-Generational National Center of Atmospheric Research/Pennsylvania State University (NCAR/PSU) Mesoscale Model (MM5) and Community Multiscale Air Quality (CMAQ) system, it was demonstrated in the first part of my thesis research that the vertical resolution of model grid affected the ozone vertical profile, and the difference of hourly average ozone concentration could be up to 46%. And the detailed processes were also studied by integrated process rate (IPR) analysis method. With the development of economics urbanization, the building availability plays an important role in air pollution transport. The mechanical impact of building availability on wind speed reduction was investigated by mesoscale meteorological model (WRF) with Building Environment Parameterization (BEP) module. Further, its downstream impact on PM10 transport was studied by CMAQ. The wind speed reduction associated with building availability could be up to 80%. And this wind speed reduction could lead to increase of PM10 15% in day time while 50% in night time.