A robot cleaner having an improved structure which executes a cleaning operation without stoppage of travelling of the robot cleaner due to obstacles present in a space to be cleaned, and a control method thereof. The control method of the robot cleaner which is provided with a main body, driving wheels driving the main body, and driving wheel assemblies, each of which includes each driving wheel, includes detecting displacement of each driving wheel with respect to a reference position by sensing a sensed body provided on each driving wheel assembly, judging whether or not the displacement is within a predetermined reference range, and changing a travelling path of the main body, upon judging that the displacement deviates from the reference range.