A cable management system includes a sliding rail setcable and management racks coupled to the sliding rail set. Each cable management rack includes a first mounting member affixed to one respective inner sliding rail of the sliding rail set, a second mounting member affixed to a link between two intermediate sliding rails of the sliding rail set, a hinge, and a first support member and a second support member respectively made by bending a respective metal wire rod into shape and respectively pivotally connected between the first and second mounting members and two opposite ends of the hinge. Thus, a large open space is defined in each of the first support member and the second support member for air circulation and heat dissipation.