Setting in the youshui Bridge Project and referring to the stipulation on the temperature gradient in current code, this aims to investigate the effects on the stress condition of concrete box-girder bridges caused by the overall heating, cooling or standard temperature changes. The process was carried out by virtue of the general finite element analysis software-MIDAS/CIVIL. The result showed that temperature would greatly affect the structural behavior of a bridge, in particular that the stress condition of the top plate is sensitive to temperature changes. It was therefore suggested that cl...