A flexible flat cable testing system includes a first connector including a row of first contacts electrically contacting first ends of a row of wires of a flexible flat cable, a second connector including a row of second contacts electrically contacting second ends of the row of wires, a short circuit test unit including output ports electrically connected to the row of first contacts and input ports electrically connected to the row of second contacts, a potential reader reading a potential level of each of the input ports, and a judgment unit determining whether or not a quality of the flexible flat cable is qualified according to the potential level of each of the input ports. The judgment unit determines that the quality of the flexible flat cable is qualified if the potential level of each of the input ports is equal to a high level output by each of the output ports.