The roof garden has great functioning of smoothing the shortage of land resource in the city and making use of the land resource diversity and efficiently. It is an efficient and reasonable way to exploit the open space the roof of the building. From the classic roof garden of the world, we can find out that roof garden has close relationship with the building. Roof garden is different with other kind landscape in the city, it needed cooperation of landscape architect and architect from at the stages of design, construction, upholding and management. We should attach importance to roof garden in the construction of building.