A planting system of building is disclosed. The planting system comprises an operation host, a hanging device, and a platform having two robotic arms with an adjustable distance between them. The hanging device is detachable disposed on the building or on the beams of the wall and connected to the platform for enabling the platform moving along the wall of the building. The operation host has a planting location defining module for defining the location of the planting, a planting growth determining module for determining the growth of the planting, and a controlling module for controlling the hanging device and the robotic arms. Wherein, the controlling module controls the hanging device to move the platform avoiding the obstacles of the building and to the location of the planting for controlling the robotic arms processing the planting.
