Knowledge of wind effects is of great significance in structural, environmental, and architectural fields, where excessive relevance among wind pressure, building load, and natural ventilation has been formerly confirmed. Within the scope of high-rise buildings, functions of their layout, separation and height in altering wind pressure have been inquired on purpose, while a few investigations in relation to impacts of plane dimensions have been explored. This study consequently intends to ascertain wind pressure distributions on and around various squared-shaped tall buildings by the application of Computational Fluid Dynamics techniques. To start with, models established by the Common Advisory Aeronautical Research Council (CAARC) were simulated, for the purpose of correctness comparison, and reliability verification. Hereafter, wind pressure distributing on buildings was predicted under two scenarios, namely height-width (HW) and height-thickness (HT). Results evidenced that both HW ratio and HT ratio exerted great influence on wind characteristics of buildings. Positive pressure on building surface generally varied greatly, where a narrower windward tended to suffer higher wind pressures, while a larger one was corresponding to severer negative wind effects. The thickness played little influence on altering positive wind pressure. Prominently, pressure distributed on leeward surfaces showed great differences, whereas wind effects on leeward and side surface were strengthened. Likewise, both positive and negative effects around buildings were magnified by larger widths, while negative effects became feeble along the increasing building thickness.