The aim of the present study is to detect the surface temperature of the green roofs by using infrared thermography, and then analyze the roof greening’s effect on thermal environment. The slope roof greening, lightweight roof greening and water storage roof greening’s infrared thermal images were shot in a cloudy day, a day after the rain and a sunny day, and then the same day and different days’ surface temperatures of the three typical green roof were compared. The results show that the green roofs’ surface temperature are mainly under the influence of solar radiation and air temperature, and water storage green roof’s surface temperature is also influenced by its water content. Roof greening can effectively reduce the roof surface temperature and decrease the range of temperature fluctuation in any weather conditions.