The global warming effect causes climate change. Especially, it directly affects the weather pattern of Taiwan. The temperature continually rising leads to higher energy consumption for building air-conditioning. The phenolic resin board is a very good heat insulation and eco-friendly construction material. Otherwise, a green roof covered with living plants for the purpose to reduce heat effect in building are widely used in the world. Therefore, in this research, the phenolic resin board is used as an experimental roof insulation material in a green roof that is covered with living plants for the objective of reducing summer building air conditioning energy consumption and cost. During summer, the difference between inside and outside temperatures across the phenolic resin board exposed to direct sun shine is as high as 8°C±2°C. The combined insulation technology using phenolic resin board and planted green vegetation coverage on the roof will also contribute to a green and aesthetic environment.