An artificial floating island includes a lower mounting and an upper mounting. The upper mounting includes a bottom wall and a surrounding wall that cooperatively define an internal space. The surrounding wall has service openings and root through holes. The upper mounting has internal blocks, each having a block body that is connected between the bottom wall and the surrounding wall, and that defines a service space disposed outside of the upper mounting and being in communication with a respective one of the service openings. The lower mounting is coupled to the upper mounting and has an outer surface that is formed with a plurality of guiding troughs.