With the rapid development of urbanization, the buildings have become one of the most important factors affecting the temperature observation. In order to research the effect of buildings on surrounding air temperature quantitatively, the city sub-domain scale model was used to simulate the influence of a single building (length of 60 m and width of 20 m) on the air temperature change, which is on the grass, under different heights (6, 18, 30 m) and different initial wind speeds (2, 4, 6, 8, 10 m·s^-1). The results showed that:(1) Because of the existence of buildings, the air temperature increased by 2.4℃ at 14:00 BST and reduced by 1℃, 2.4℃ at 20:00 BST, 02:00 BST, respectively. (2)The maximum influence distance of buildings on the leeward temperature was 11.7 times the height of the building at 14:00 BST, and it was 36.7 and 21.7 times the height of the building at 20:00 BST and 02:00 BST, which beyond the value of regulation. (3)The wind speed attenuation caused by the buildings increases the mechanical term in the turbulent kinetic energy, namely; the stronger the wind speed attenuation, the greater the effect on the air temperature change. In addition, during the daytime, the solar radiation shielding caused by the buildings also has a certain influence. This means that when the building is higher, it will weaken the effect of temperature increase to some extent.