A protecting device for enclosing cable connectors of a computer comprises a rear panel (10) of a computer chassis, a first member (20) and a second member (30). The rear panel has a plurality of I/O ports (102) for the cable connectors inserting thereinto. The first member attached to the rear panel has at least one first cutout (243, 245). The second member couples to the first member for enclosing the cable connectors, and has at least one second cutout (343, 345) matching the first cutout to provide passages for cables of the cable connectors. The cables are distributed in the passages. The cable connectors are prevented being removed from the first and second members.