A cleaning system may include a first mobile robot, a communication unit configured to communicate with a second mobile robot that emits a second signal, and a controller configured to recognize the location of the second mobile robot using the second signal, and control a moving speed of the first mobile robot such that the second mobile robot follows a trajectory corresponding to the movement of the first mobile robot based on the recognized location. The controller may transmit a first signal to the second mobile robot in response to the first mobile robot approaching the second mobile robot to within a distance less than a threshold distance from the second mobile robot, and control avoidance moving of the first mobile robot and the second mobile robot based on the second signal of the second mobile robot responding to the first signal.