Suspended particles have already become the biggest air pollution index of urban air quality that is also harmful for human health. Suspended particles in the urban areas would be mostly removed by air draft in the urban wind field. The wind field is subject to urban block types, the building structure, the urban streets, the open space etc. This study would examine more closely how intensively the urban block types would effect the particle distribution, so that it will provide the urban plan and relative regulation to refer. This experiment would choose urban block types for an object inside the downtown area in Taipei, measure the suspended particles respectively before dismantling, under dismantling and after dismantling three stages, then draw the results in the GIS system to demonstrate the discolored density equivalent diagram with the application of the space, analyze out the different urban block types changing on the distribution of suspended particles and also apply for the simulation with FLOVENT5.1 software. The results demonstrate as following: 1.Before deconstruction: the dense urban blocks result as a hindering of draft of the air pollutants. Under deconstruction: the sprinkler system reduces the PM10 concentration 20% to 30%. After deconstruction: the changes of urban block types reduce the PM10 concentration 50%, add the wind speed 0.25m/s and affects surrounding environment up to 50 meters by distance. 2. After building: technology building is 16 feet high. It will bring bigger turbulent flow and affect surrounding environment. One floor ventilated plan will reduce the PM10 concentration 63%. 3. In the future, the issue of suspended particles is to be considered in the urban plan, urban design regulations, building codes etc.