Abstract: Thermal insulation of green roof is particularly important for reducing energy consumption of air conditioners in summer. At present, there is no comprehensive study on the diurnal thermal effects in summer under various sunshine environments. This study analyzes the diurnal heat insulation effects of the sedum module green roof in Shanghai. The trial roof was divided into four sunshine zones. The environment temperature data were monitored and collected by HOBO U30 USB Station. The multi-point temperature data were continuously measured by thermocouples in different sunshine zones day and night. The results show that 1) during the daytime, the heat insulation effect of the trial green roof is obvious (more than 28℃ cut of surface temperature in maximum) and the stronger the sunshine, the more obvious the effect; 2) The heat dissipation effect of the green roof is not as good as the bare roof during the night; and 3) There are delays of the highest temperature appearance for the green roof. From the view of comprehensive diurnal building energy conservation, further studies are needed on the thermal insulation performance of roof structure, the sunshine condition of roof and the daily use of buildings to optimize the investment and energy efficiency of green roof.