An apparatus and method for identifying paper cassettes. The apparatus for identifying paper cassettes includes first through N-th paper cassettes, wherein each of N-1 output ports (where N is a positive integer greater than 1) is connected to N-1 input ports, which have one of N input ports and one of N output ports, a paper cassette identification unit to generate a synchronizing signal in response to an identification symbol which is transmitted from the first through N-th paper cassettes and indicates one of the first through N-th paper cassettes, and to transmit the generated synchronizing signal to paper cassettes in which an "undefined symbol" that indicates that the identification symbol has not been assigned, among the first through N-th paper cassettes is given, and a serial bus which connects the first through N-th paper cassettes to the paper cassette identification unit.