Although China is a developing country, the energy consumption in China already becomes number one in the world. At the same time, the average energy efficiency on the utilization of primary energy resources is only 30%. The building energy consumption in China accounts for 30% in 2009 and still keeps increasing. There is a need to increase the energy performance of the buildings thus to reduce the total energy consumption. Of the various thermal loads, one from the building roof accounts for about 20–40% in China, therefore, it is very important to improve the building roof thermal performance. Green roof is one of the measures that can help to improve the building energy performance and reduce the building energy consumption.