A clothes treating system includes a first clothes treating apparatus including a first drum, a first controller configured to control an operation of the first drum, and a diagnostic port; and a second clothes treating apparatus including a second drum, and a second controller configured to control an operation of the second drum. The first controller includes a first transmitting end and a first receiving end, and is configured to receive a first diagnosis request signal from the diagnostic port through the first receiving end, identify a diagnosis target based on the first diagnosis request signal, transmit a first diagnosis result signal to the diagnostic port through the first transmitting end after performing a diagnostic operation corresponding to the first diagnosis request signal in response to the diagnosis target being identified as the first clothes treating apparatus, and in response to the diagnosis target being identified as the second clothes treating apparatus, transmit a second diagnosis request signal to the second controller through the first transmitting end.