A digital broadcasting system and method, where the digital broadcasting system includes: a transmission stream generator multiplexing a normal stream and a turbo stream to generate a dual transmission stream; a transmitter inserting an supplementary reference signal (SRS) into the dual transmission stream, processing the turbo stream to reconstitute the dual transmission stream, and outputting the reconstituted dual transmission stream; and a receiver receiving the reconstituted dual transmission stream, separately turbo decoding the turbo stream, inserting the turbo decode turbo stream into the dual transmission stream, and decoding the dual transmission stream into which the turbo decoded turbo stream has been inserted, to restore normal stream data and turbo stream data. Thus, reception sensitivity of a digital broadcasting signal can be efficiently improved.