Through numerical simulation method to simulate the whole process from construction period to operation period and untill the time when the temperature of dam body reaches stability for the dam body structure and its foundation of the leftguide wall dam section of TGP,a study on the temperature field and the temperature stress distribution of the dam section and their duration change regularitiesis performed.On the basis of the result,an assessment on the problem of temperature control for the left guidewall of TGP is made,and the measures of temperature control for the dam section are proposed.