Roof greening can increase areas of green and improve ecological environment in city.Based on roof greening in low energy demo building of Tsinghua University,This paper analyses the temperature distributed character and ecological effect of roof greening.The result show that roof greening can adjust the microclimate.The cool effect of vegetation roof is very distinctness at 12:00 to 16:00.It decrease temperature 4 ℃ and reduce the duration time of high temperature in summer,with seasonal variation,the cool effect is decreased.The temperature distribution in autumn is similar with summer.The preserve heat in winter is not obvious than the cool effect in summer.The mean temperature on vegetation roof is higher than cement roof,and the effect is an accumulative process.The thermal distributions is important to relation of roof greening and environment,it can provide scientific basis for the construction and development of roof greening.
