The invention relates to a signal driving system for a display. The signal driving system comprises: a signal controller, a flexible connector and a plurality of driving devices. The signal controller is used to produce a first control signal. The flexible connector is connected to the signal controller, and used to receive the first control signal. One of the driving devices is connected to the flexible connector. The driving devices connect in cascade. Each driving device comprises a data input port, a data output port and a driving signal output port. The data input port receives the first control signal or a second control signal. The data output port outputs the second control signal. According to the first control signal or the second control signal, the driving signal output port transmits a driving signal. The signal driving system of the invention can make the data output port of the driving device transmit the second control signal to the next driving device. Therefore, the signal driving system of the invention can resolve the problem between different control signals of different circuit interfaces. Besides, the signal driving system of the invention has the advantage of processing the first control signal in the signal controller and transmitting the second control signal between the driving devices.